Mobile security

Mobile security, or mobile device security, is the protection of smartphones, tablets, and laptops from threats associated with wireless computing. It has become increasingly important in mobile computing. The security of personal and business information now stored on smartphones is of particular concern.
Increasingly, users and businesses use smartphones not only to communicate, but also to plan and organize their work and private life. Within companies, these technologies are causing profound changes in the organization of information systems and have therefore become the source of new risks. Indeed, smartphones collect and compile an increasing amount of sensitive information to which access must be controlled to protect the privacy of the user and the intellectual property of the company.
The majority of attacks are aimed at smartphones. These attacks take advantage of vulnerabilities discovered in smartphones that can result from different modes of communication, including Short Message Service, Multimedia Messaging Service, wireless connections, Bluetooth, and GSM, the de facto international standard for mobile communications. Smartphone operating systems or browsers are another weakness. Some malware makes use of the common user's limited knowledge. Only 2.1% of users reported having first-hand contact with mobile malware, according to a 2008 McAfee study, which found that 11.6% of users had heard of someone else being harmed by the problem. Yet, it is predicted that this number will rise. As of December 2023, there were about 5.4 million global mobile cyberattacks per month. This is a 147% increase from the previous year.
Security countermeasures are being developed and applied to smartphones, from security best practices in software to the dissemination of information to end users. Countermeasures can be implemented at all levels, including operating system development, software design, and user behavior modifications.

Challenges of smartphone mobile security

Threats

A smartphone user is exposed to various threats when they use their phone. In just the last two quarters of 2012, the number of unique mobile threats grew by 261%, according to ABI Research. These threats can disrupt the operation of the smartphone and transmit or modify user data. Applications must guarantee privacy and integrity of the information they handle. In addition, since some apps could themselves be malware, their functionality and activities should be limited. Malicious apps can also be installed without the owners' permission or knowledge.
Vulnerability in mobile devices refers to aspects of system security that are susceptible to attacks. A vulnerability occurs when there is system weakness, an attacker has access to the weakness, and the attacker has competency to exploit the weakness.
Potential attackers began looking for vulnerabilities when Apple's iPhone and the first Android devices came onto the market. Since the introduction of apps, which are vital targets for hackers, malware has been rampant. The Department of Homeland Security's cybersecurity department claims that the number of vulnerable points in smartphone operating systems has increased. As mobile phones are connected to utilities and appliances, hackers, cybercriminals, and even intelligence officials have access to these devices.
Starting in 2011, it became increasingly popular to let employees use their own devices for work-related purposes. The Crowd Research Partners study, published in 2017, reports that during 2017, most businesses that mandated the use of mobile devices were subjected to malware attacks and breaches. It has become common for rogue applications to be installed on user devices without the user's permission. They breach privacy, which hinders the effectiveness of the devices.
Since the recent rise of mobile attacks, hackers have increasingly targeted smartphones through credential theft and snooping. The number of attacks targeting smartphones and other devices has risen by 50 percent. According to the study, mobile banking applications are responsible for the increase in attacks.
Malware—such as ransomware, worms, botnets, Trojans, and viruses—have been developed to exploit vulnerabilities in mobile devices. Malware is distributed by attackers so they can gain access to private information or digitally harm a user. For example, should malware breach a user's banking service, it may be able to access their transaction information, their rights to log in, and their money. Some malware is developed with anti-detection techniques to avoid detection. Attackers who use malware can avoid detection by hiding malicious code.
Trojan-droppers can also avoid detection of malware. Despite the fact that the malware inside a device does not change, the dropper generates new hashes each time. Additionally, droppers can also create a multitude of files, which can lead to the creation of viruses. Android mobile devices are prone to Trojan-droppers. The banking Trojans also enable attacks on the banking applications on the phone, which leads to the theft of data for use in stealing money and funds.
Jailbreaks for iOS devices work by disabling the signing of codes on iPhones so that applications not downloaded from the App Store can be operated. In this way, all the protection layers offered by iOS are disrupted, exposing the device to malware. These outside applications don't run in a sandbox, which exposes potential security problems. Some attack vectors change the mobile devices' configuration settings by installing malicious credentials and virtual private networks to direct information to malicious systems. In addition, spyware can be installed on mobile devices in order to track an individual.
Triade malware comes pre-installed on some mobile devices. In addition to Haddad, there is Lotoor, which exploits vulnerabilities in the system to repackage legitimate applications. The devices are also vulnerable due to spyware and leaky behaviors through applications. Mobile devices are also effective conveyance systems for malware threats, breaches of information, and thefts.
Wi-Fi interference technologies can also attack mobile devices through potentially insecure networks. By compromising the network, hackers are able to gain access to key data. Devices connected to public networks are at risk of attacks. A VPN, on the other hand, can be used to secure networks. As soon as a system is threatened, an active VPN will operate. There are also social engineering techniques, such as phishing, in which unsuspecting victims are sent links to lead them to malicious websites. The attackers can then hack into the victim's device and copy all of its information.
Some mobile device attacks can be prevented. For example, containerization allows the creation of a hardware infrastructure that separates business data from other data. Additionally, network protection detects malicious traffic and rogue access points. Data security is also ensured through authentication.
There are a number of threats to mobile devices, including annoyance, stealing money, invading privacy, propagation, and malicious tools. There are three prime targets for attackers:

Data – Smartphones are devices for data management and may contain sensitive data like credit card numbers, authentication information, private information, activity logs.
Identity – Smartphones are highly customizable, so the device or its contents can easily be associated with a specific person.
Availability – Attacking a smartphone can limit or deprive a user's access to it.

Attacks on mobile security systems include:

Botnets – Attackers infect multiple machines with malware that victims generally acquire via e-mail attachments or from compromised applications or websites. The malware then gives hackers remote control of "zombie" devices, which can then be instructed to perform harmful acts.
Malicious applications – Hackers upload malicious programs or games to third-party smartphone application marketplaces. The programs steal personal information and open backdoor communication channels to install additional applications and cause other problems.
Malicious links on social networks – An effective way to spread malware where hackers can place Trojans, spyware, and backdoors.
Spyware – Hackers use this to hijack phones, allowing them to hear calls, see text messages and e-mails, and track a user's location through GPS updates.

The source of these attacks are the same actors found in the non-mobile computing space:

Professionals, whether commercial or military, who focus on the three targets mentioned above. They steal sensitive data from the general public, as well as undertake industrial espionage. They will also use the identity of those attacked to achieve other attacks.
Thieves who want to gain income through data or identities they have stolen. The thieves will attack many people to increase their potential income.
Black hat hackers who specifically attack availability. Their goal is to develop viruses, and cause damage to the device. In some cases, hackers have an interest in stealing data on devices.
Grey hat hackers who reveal vulnerabilities. Their goal is to expose vulnerabilities of the device. Grey hat hackers do not intend on damaging the device or stealing data.
Consequences

When a smartphone is infected by an attacker, the attacker can attempt several things:

The attacker can manipulate the smartphone as a zombie machine: a machine with which the attacker can communicate and send commands which will be used to send unsolicited messages via SMS or email.
The attacker can easily force the smartphone to make phone calls. For example, one can use the API PhoneMakeCall by Microsoft, which collects telephone numbers from any source and then calls them. The attacker can use this method to call paid services, resulting in charges to the smartphone owner. Dangerously, the smartphone could call and disrupt emergency services.
A compromised smartphone can record conversations between the user and others and send them to a third party. This can cause user privacy and industrial security problems.
An attacker can also steal a user's identity, usurp their identity, and thus impersonate the owner. This raises security concerns in countries where smartphones can be used to place orders, view bank accounts, or are used as an identity card.
The attacker can reduce the usability of the smartphone, by discharging the battery. For example, they can launch an application that will run continuously on the smartphone processor, requiring a lot of energy and draining the battery. Frank Stajano and Ross Anderson first described this form of attack, calling it an attack of "battery exhaustion" or "sleep deprivation torture".
The attacker can make the smartphone unusable. This attack can delete the boot scripts, resulting in a phone without a functioning operating system; modify certain files to make it unusable, such as a script that launches at startup that forces the smartphone to restart; or embed a startup application that will empty the battery.
The attacker can remove the user's data, whether personal or professional.
Attacks based on communication

Attacks based on SMS and MMS

Some attacks derive from flaws in the management of Short Message Service and Multimedia Messaging Service.
Some mobile phone models have problems in managing binary SMS messages. By sending an ill-formed block, it is possible to cause the phone to restart, leading to the denial-of-service attacks. If a user with a Siemens S55 received a text message containing a Chinese character, it would lead to a denial of service.
In another case, while the standard requires that the maximum size of a Nokia Mail address is 32 characters, some Nokia phones did not verify this standard, so if a user enters an email address over 32 characters, that leads to complete dysfunction of the e-mail handler and puts it out of commission. This attack is called "curse of silence".
A study on the safety of the SMS infrastructure revealed that SMS messages sent from the Internet can be used to perform a distributed denial of service attack against the mobile telecommunications infrastructure of a big city. The attack exploits the delays in the delivery of messages to overload the network.
Another potential attack could begin with a phone that sends an MMS to other phones, with an attachment. This attachment is infected with a virus. Upon receipt of the MMS, the user can choose to open the attachment. If it is opened, the phone is infected, and the virus sends an MMS with an infected attachment to all the contacts in the address book. There is a real-world example of this attack: the virus Commwarrior sends MMS messages to all recipients in a mobile phone's address book. If a recipient installs the infected file, the virus repeats, sending messages to recipients taken from the new address book.

Attacks based on communication networks

GSM networks

The attacker may try to break the encryption of a GSM mobile network. The network encryption algorithms belong to the family of algorithms called A5. Due to the policy of security through obscurity, it has not been possible to openly test the robustness of these algorithms. There were originally two variants of the algorithm: A5/1 and A5/2, where the former was designed to be relatively strong, and the latter was purposely designed to be weak to allow easy cryptanalysis and eavesdropping. ETSI forced some countries to use A5/2. Since the encryption algorithm was made public, it was proved to be breakable: A5/2 could be broken on the fly, and A5/1 in about 6 hours. In July 2007, the 3GPP approved a change request to prohibit the implementation of A5/2 in any new mobile phones, decommissioning the algorithm; it is no longer implemented in mobile phones.
Stronger public algorithms have been added to the GSM standard: the A5/3 and A5/4, otherwise known as KASUMI or UEA1 published by ETSI. If the network does not support A5/1, or any other A5 algorithm implemented by the phone, then the base station can specify A5/0 which is the null algorithm, whereby the radio traffic is sent unencrypted. Even if mobile phones are able to use 3G or 4G, the base station can downgrade the radio communication to 2G GSM and specify A5/0. This is the basis for eavesdropping attacks on mobile radio networks using a fake base station commonly called an IMSI catcher.
In addition, tracing of mobile terminals is difficult since each time the mobile terminal is accessing or being accessed by the network, a new temporary identity is allocated to the mobile terminal. The TMSI is used as the identity of the mobile terminal the next time it accesses the network. The TMSI is sent to the mobile terminal in encrypted messages.
Once the encryption algorithm of GSM is broken, the attacker can intercept all unencrypted communications made by the victim's smartphone.

Wi-Fi

An attacker can try to eavesdrop on Wi-Fi communications to derive information. This type of attack is not unique to smartphones, but they are very vulnerable to these attacks because often Wi-Fi is their only means of communication and access the internet. The security of wireless networks is thus an important subject.
Initially, wireless networks were secured by WEP keys. The weakness of WEP is its short encryption key, which is the same for all connected clients. In addition, several reductions in the search space of the keys have been found by researchers. Now, most wireless networks are protected by the WPA security protocol. WPA is based on the Temporal Key Integrity Protocol, which was designed to allow migration from WEP to WPA on the equipment already deployed. The major improvements in security are the dynamic encryption keys. For small networks, the WPA uses a "pre-shared key" which is based on a shared key. Encryption can be vulnerable if the length of the shared key is short. With limited opportunities for input, mobile phone users might define short encryption keys that contain only numbers. This increases the likelihood that an attacker succeeds with a brute-force attack. The successor to WPA, called WPA2, is supposed to be safe enough to withstand a brute force attack.
The ability to access free and fast Wi-Fi gives a business an edge over those who do not. Free Wi-Fi is usually provided by organizations such as airports, coffee shops, and restaurants for a number of reasons, including encouraging customers to spend more time and money on the premises, and helping users stay productive. Another reason is enhancing customer tracking: many restaurants and coffee shops compile data about their customers so they can target advertisements directly to their devices. This means that customers know what services the facility provides. Generally, individuals filter business premises based on Internet connections as another reason to gain a competitive edge. Network security is the responsibility of the organizations, as unsecured Wi-Fi networks are prone to numerous risks. The man-in-the-middle attack entails the interception and modification of data between parties. Additionally, malware can be distributed via the free Wi-Fi network and hackers can exploit software vulnerabilities to smuggle malware onto connected devices. It is also possible to eavesdrop and sniff Wi-Fi signals using special software and devices, capturing login credentials and hijacking accounts.
As with GSM, if the attacker succeeds in breaking the identification key, both the phone and the entire network it is connected to become exposed to attacks.
Many smartphones remember wireless LANs they have previously connected to, allowing users to not have to re-identify with each connection. However, an attacker could create a Wi-Fi access point twin with the same parameters and characteristics as a real network. By automatically connecting to the fraudulent network, a smartphone becomes susceptible to the attacker, who can intercept any unencrypted data.
Lasco is a worm that initially infects a remote device using the SIS file format, a type of script file that can be executed by the system without user interaction. The smartphone thus believes the file to come from a trusted source and downloads it, infecting the machine.

Bluetooth

Security issues related to Bluetooth on mobile devices have been studied and have shown numerous problems on different phones. One easy to exploit vulnerability is that unregistered services do not require authentication, and vulnerable applications have a virtual serial port used to control the phone. An attacker only needed to connect to the port to take full control of the device.
In another example, an attacker sends a file via Bluetooth to a phone within range with Bluetooth in discovery mode. If the recipient accepts, a virus is transmitted. An example of this is a worm called Cabir. The worm searches for nearby phones with Bluetooth in discoverable mode and sends itself to the target device. The user must accept the incoming file and install the program, after which the worm infects the machine.

Attacks based on vulnerabilities in software applications

Other attacks are based on flaws in the OS or applications on the phone.

Web browser

The mobile web browser is an emerging attack vector for mobile devices. Just as common Web browsers, mobile web browsers are extended from pure web navigation with widgets and plug-ins or are completely native mobile browsers.
Jailbreaking the iPhone with firmware 1.1.1 was based entirely on vulnerabilities on the web browser. In this case, there was a vulnerability based on a stack-based buffer overflow in a library used by the web browser. A similar vulnerability in the web browser for Android was discovered in October 2008. Like the iPhone vulnerability, it was due to an obsolete and vulnerable library, but significantly differed in that Android's sandboxing architecture limited the effects of this vulnerability to the Web browser process.
Smartphones are also victims of classic Web piracy such as phishing, malicious websites, and background-running software. The big difference is that smartphones do not yet have strong antivirus software available.
Industry mobile security research also highlights rising risks from application reverse engineering, runtime tampering, and API exploitation in mobile apps.
The Internet offers numerous interactive features that ensure a higher engagement rate, capture more and relevant data, and increase brand loyalty. Blogs, forums, social networks, and wikis are some of the most common interactive websites. Due to the tremendous growth of the Internet, there has been a rapid rise in the number of security breaches experienced by individuals and businesses.
Mobile browser users can balance usage and caution in several ways, such as reviewing computer security regularly, using secure and secret passwords, and correcting, upgrading, and replacing the necessary features. Installation of antivirus and anti-spyware programs is the most effective way of protecting the computer, as they offer protection against malware, spyware, and viruses. Additionally, they use firewalls, which are typically installed between trusted networks or devices and the Internet. By acting as a web server, the firewall prevents external users from accessing the internal computer system.

Operating system

Sometimes it is possible to overcome the security safeguards by modifying the operating system itself, such as the manipulation of firmware and malicious signature certificates. These attacks are difficult.
In 2004, vulnerabilities in virtual machines running on certain devices were revealed. It was possible to bypass the bytecode verifier and access the native underlying operating system. The results of this research were not published in detail. The firmware security of Nokia's Symbian Platform Security Architecture is based on a central configuration file called SWIPolicy. In 2008, it was possible to manipulate the Nokia firmware before it was installed. In fact, some downloadable versions of this file were human-readable, so it was possible to modify and change the image of the firmware. This vulnerability was solved by an update from Nokia.
In theory, smartphones have an advantage over hard drives since the OS files are in read-only memory and cannot be changed by malware. However, in some systems it was possible to circumvent this: in the Symbian OS, it was possible to overwrite a file with a file of the same name. On the Windows OS, it was possible to change a pointer from a general configuration file to an editable file.
When an application is installed, the signing of this application is verified by a series of certificates. One can create a valid signature without using a valid certificate and add it to the list. In the Symbian OS, all certificates are in the directory. With firmware changes explained above, it is very easy to insert a seemingly valid but malicious certificate.
Android is the OS that has been attacked the most, because it has the largest userbase. A cybersecurity company reported to have blocked about 18 million attacks in 2016.

Attacks based on hardware vulnerabilities

Electromagnetic waveforms

In 2015, researchers at the French government agency Agence nationale de la sécurité des systèmes d'information demonstrated the capability to trigger the voice interface of certain smartphones remotely by using "specific electromagnetic waveforms". The exploit took advantage of antenna-properties of headphone wires while plugged into the audio-output jacks of the vulnerable smartphones and effectively spoofed audio input to inject commands via the audio interface.

Juice jacking

Juice jacking is a physical or hardware vulnerability specific to mobile platforms. Utilizing the dual purpose of the USB charge port, many devices have been susceptible to having data exfiltrated from, or malware installed onto, a mobile device by utilizing malicious charging kiosks set up in public places or hidden in normal charge adapters.

Jailbreaking and rooting

Jailbreaking is also a physical access vulnerability, in which a mobile device user hacks into device to unlock it, exploiting weaknesses in the operating system. Mobile device users take control of their own device by jailbreaking it, allowing them to customize the interface by installing applications, change system settings that are not allowed on the devices, tweak OS processes, and run uncertified programs. This openness exposes the device to a variety of malicious attacks which can compromise private data.

Password cracking

In 2010, researchers from the University of Pennsylvania investigated the possibility of cracking a device's password through a smudge attack. The researchers were able to discern the device password up to 68% of the time under certain conditions. Outsiders may perform over-the-shoulder surveillance on victims, such as watching specific keystrokes or pattern gestures, to unlock device password or passcode.

Malicious software (malware)

As smartphones are a permanent point of access to the Internet, they can be compromised with malware as easily as computers. A malware is a computer program that aims to harm the system in which it resides.
Trojans, worms and viruses are all considered malware. A Trojan is a program on a device that allows external users to connect discreetly. A worm is a program that reproduces on multiple computers across a network. A virus is a malicious software designed to spread to other computers by inserting itself into legitimate programs and running programs in parallel.
Malware is far less numerous and serious to smartphones as it is to computers. Nonetheless, recent studies show that the evolution of malware in smartphones have rocketed in the last few years posing a threat to analysis and detection. In 2017, mobile malware variants increased by 54%.

Problematic common apps and pre-installed software

Various common apps installed by millions can intrude on privacy, even if they were installed from a trusted software distribution service like the Google Play Store. For example, in 2022 it was shown that the popular app TikTok collects a lot of data and is required to make it available to the Chinese Communist Party due to a national security law. This includes personal information on millions of Americans.
The firmware and "stock software" preinstalled on devices – and updated with preinstalled software – can also have undesired components or privacy-intruding default configurations or substantial security vulnerabilities. In 2019, Kryptowire identified Android devices with malicious firmware that collected and transmitted sensitive data without users' consent.
Analysis of data traffic by popular smartphones running variants of Android found substantial by-default data collection and sharing with no opt-out by pre-installed software. This issue also can't be addressed by conventional security patches. Outgoing Internet traffic can be analyzed with packet analyzers and with firewall apps like the NetGuard firewall app for Android that allows reading blocked traffic logs.

Malware attacks

Typically, an attack on a smartphone made by malware takes place in three phases: the infection of a host, the accomplishment of its goal, and the spread of the malware to other systems. Malware often uses the resources offered by infected smartphones. It will use the output devices such as Bluetooth or infrared, but it may also use the address book or email address of the person to infect the user's acquaintances. The malware exploits the trust that is given to data sent by an acquaintance.

Infection

Infection is the method used by malware to gain access to the smartphone; it may exploit an internal vulnerability or rely on the gullibility of the user. Infections are classified into four classes according to their degree of user interaction:

Explicit permission – The most benign interaction is to ask the user if it is allowed to infect the machine, clearly indicating its potential malicious behavior. This is typical behavior of a proof of concept malware.
Implied permission – This infection is based on the fact that the user has a habit of installing software. Most Trojans try to seduce the user into installing attractive applications that actually contain malware.
Common interaction – This infection is related to a common behavior, such as opening an MMS or email.
No interaction – The device is infected without the user taking action. This class of infection is the most dangerous, as it is both unapproved and automatic.

Accomplishment of its goal
Once the malware has infected a phone, it will also seek to accomplish its goal, which is usually one of the following:

Monetary damages – The attacker can steal user data and either sell them to the same user or sell to a third party.
Data or device damage – Malware can partially damage the device or delete or modify data on the device.
Concealed damage – The two aforementioned types of damage are detectable, but the malware can also leave a backdoor for future attacks or even conduct wiretaps.
Spread to other systems

Once the malware has infected a smartphone, it aims to spread to a new host. This usually occurs to proximate devices via Wi-Fi, Bluetooth, or infrared; or to remote networks via telephone calls, SMS, or emails.

Examples

Viruses and Trojans

Cabir is the name of a computer worm developed in 2004, designed to infect mobile phones running Symbian OS. It is believed to have been the first computer worm able to infect mobile phones.
Commwarrior, created on March 7, 2005, was the first worm able to infect many machines from MMS. It is sent as COMMWARRIOR.ZIP containing the file COMMWARRIOR.SIS. When this file is executed, Commwarrior attempts to connect to nearby devices by Bluetooth or infrared under a random name. It then attempts to send MMS message to the contacts in the smartphone with different header messages for each person, who receive the MMS and often open them without further verification.
Phage was the first Palm OS virus discovered. It transfers to the Palm from a PC via synchronization. It infects all applications in the smartphone and embeds its own code to function without the user and the system detecting it. From the system's perspective, all the applications behave as expected.
RedBrowser is a Trojan based on Java. The Trojan masquerades as a program called "RedBrowser" which allows the user to visit WAP sites without a WAP connection. During application installation, the user sees a request on their phone that the application needs permission to send messages. If the user accepts, RedBrowser can send SMS to paid call centers. This program uses the smartphone's connection to social networks to get the contact information for the user's acquaintances and will send them messages.
WinCE.PmCryptic.A is a malicious software on Windows Mobile which aims to earn money for its authors. It uses the infestation of memory cards that are inserted in the smartphone to spread more effectively.
CardTrap is a virus that is available on different types of smartphones, which aims to deactivate the system and third-party applications. It works by replacing the files used to start the smartphone and applications to prevent them from executing. There are different variants of this virus such as Cardtrap.A for SymbOS devices. It also infects the memory card with malware capable of infecting Windows.
Ghost Push is malicious software on Android OS which automatically roots the Android device and installs malicious applications directly to system partition. It then unroots the device to prevent users from removing the threat by master reset. It cripples the system resources, executes quickly, and is hard to detect.
Ransomware

Mobile ransomware is a type of malware that locks users out of their mobile devices in a pay-to-unlock-your-device ploy. It has significantly grown as a threat category since 2014. Mobile users are often less security-conscious – particularly as it pertains to scrutinizing applications and web links – and trust the mobile device's native protection capability.
Mobile ransomware poses a significant threat to businesses reliant on instant access and availability of their proprietary information and contacts. The likelihood of a traveling businessman paying a ransom to unlock their device is significantly higher since they are at a disadvantage given inconveniences such as timeliness and less direct access to IT staff. Recent ransomware attacks have caused many Internet-connected devices to not work and are costly for companies to recover from.

Spyware

Pegasus – In 2021, journalists and researchers reported the discovery of spyware developed and distributed by a private company which can and has been used to infect both iOS and Android smartphones often – partly via use of 0-day exploits – without the need for any user-interaction or significant clues to the user. The spyware is then used to exfiltrate data, track user locations, capture film through its camera, and activate the microphone at any time.
Flexispy is a Symbian application that can be considered a Trojan. The program sends all information received and sent from the smartphone to a Flexispy server. It was originally created to protect children and spy on adulterous spouses.
Portability of malware across platforms

Attackers can make their malware target multiple platforms. Some malware attacks operating systems but is able to spread across different systems.
To begin with, malware can use runtime environments like Java virtual machine or the .NET Framework. They can also use other libraries present in many operating systems. Some malware carries several executable files in order to run in multiple environments, utilizing these during the propagation process. In practice, this type of malware requires a connection between the two operating systems to use as an attack vector. Memory cards can be used for this purpose, or synchronization software can be used to propagate the virus.
Mobile security is divided into different categories, as methods do not all act at the same level and are designed to prevent different threats. These methods range from the management of security by the operating system to the behavioral education of the user.
Among the mechanisms that handle device-access protection, some services or third-party tools can assist in unlocking or resetting locked devices after a factory reset or FRP.

Security in operating systems

The first layer of security in a smartphone is the operating system. Beyond needing to handle the usual roles on the device, it must also establish the protocols for introducing external applications and data without introducing risk.
A central paradigm in mobile operating systems is the idea of a sandbox. Since smartphones are currently designed to accommodate many applications, they must have mechanisms to ensure these applications are safe for the phone itself, for other applications and data on the system, and for the user. If a malicious program reaches a mobile device, the vulnerable area presented by the system must be as small as possible. Sandboxing extends this idea to compartmentalize different processes, preventing them from interacting and damaging each other. Based on the history of operating systems, sandboxing has different implementations. For example, where iOS will focus on limiting access to its public API for applications from the App Store by default, Managed Open In allows you to restrict which apps can access which types of data. Android bases its sandboxing on its legacy of Linux and TrustedBSD.
The following points highlight mechanisms implemented in operating systems, especially Android.
; Rootkit detectors
; Process isolation
; File permissions
; Memory protection
; Development through runtime environments

Security software

Above the operating system security, there is a layer of security software. This layer is composed of individual components to strengthen various vulnerabilities: prevent malware, intrusions, the identification of a user as a human, and user authentication. It contains software components that have learned from their experience with computer security; however, on smartphones, this software must deal with greater constraints.
; Antivirus and firewall
; Visual notifications
; Turing test
; Biometric identification

Resource monitoring in the smartphone

Should a malicious application pass the security barriers, it can take the actions for which it was designed. However, this activity can be sometimes detected by monitoring the various resources used on the phone. Depending on the goals of the malware, the consequences of infection are not always the same; all malicious applications are not intended to harm the devices on which they are deployed.
The following resources are only indications and do not provide certainty about the legitimacy of the activity of an application. However, these criteria can help target suspicious applications, especially if several criteria are combined.
; Battery
; Memory usage
; Network traffic
; Services

Network surveillance

exchanged by phones can be monitored. One can place safeguards in network routing points in order to detect abnormal behavior. As the mobile's use of network protocols is much more constrained than that of a computer, expected network data streams can be predicted, which permits detection of anomalies in mobile networks.
; Spam filters
; Encryption of stored or transmitted information
; Telecom network monitoring

Manufacturer surveillance

In the production and distribution chain for mobile devices, manufacturers are responsibility for ensuring that devices are delivered in a basic configuration without vulnerabilities. Most users are not experts and many of them are not aware of the existence of security vulnerabilities, so the device configuration as provided by manufacturers will be retained by many users. Some smartphone manufacturers add Titan M2s to increase mobile security.
; Remove debug mode
; Default settings
; Security audit of apps
; Detect suspicious applications demanding rights
; Revocation procedures
; Avoid heavily customized systems
; Improve software patch processes

User awareness

The user has a large responsibility in the cycle of security. This can be as simple as using a password, or as detailed as precisely controlling which permissions are granted to applications. This precaution is especially important if the user is an employee of a company who stores business data on the device.
Much malicious behavior is allowed by user carelessness. Smartphone users were found to ignore security messages during application installation, especially during application selection and checking application reputation, reviews, security, and agreement messages. A recent survey by internet security experts BullGuard showed a lack of insight concerning the rising number of malicious threats affecting mobile phones, with 53% of users claiming that they are unaware of security software for smartphones. A further 21% argued that such protection was unnecessary, and 42% admitted it hadn't crossed their mind. These statistics show that consumers are not concerned about security risks because they believe it is not a serious problem. However, in truth, smartphones are effectively handheld computers and are just as vulnerable.
The following are precautions that a user can take to manage security on a smartphone:
; Be skeptical
; Permissions given to applications
; Be careful
;Disconnect unused peripheral devices

Enable Android Device Encryption

; Ensure data
These precautions reduce the ability for people or malicious applications to exploit a user's smartphone. If users are careful, many attacks can be defeated, especially phishing and applications seeking only to obtain rights on a device.

Centralized storage

One form of mobile protection allows companies to control the delivery and storage of text messages, by hosting the messages on a company server, rather than on the sender or receiver's phone. When certain conditions are met, such as an expiration date, the messages are deleted.

Limitations

The security mechanisms mentioned in this article are to a large extent inherited from knowledge and experience with computer security. The elements composing the two device types are similar, and there are common measures that can be used, such as antivirus software and firewalls. However, the implementation of these solutions is not necessarily possible within a mobile device. The reason for this difference is the technical resources available to computers and mobile devices: even though the computing power of smartphones is becoming faster, they have other limitations:

Single-task system – Some operating systems, including some still commonly used, are single-tasking. Only the foreground task is executed. It is difficult to introduce applications such as antivirus and firewall on such systems, because they cannot perform their monitoring while the user is operating the device, when monitoring is most needed.
Energy autonomy – A critical limitation for smartphones is energy autonomy. It is important that security mechanisms not consume too much battery resources, which could dramatically undermine the smartphone's autonomy and usage.
Network – Directly related to battery life, network utilization should not be too high. From the point of view of energy consumption, network utilization is one of the most expensive resources. Nonetheless, some calculations may need to be relocated to remote servers in order to preserve the battery. This balance can make implementation of certain intensive computation mechanisms a delicate situation.

Furthermore, it is common that even if updates exist, or can be developed, they are not always deployed. For example, a user may not be aware of operating system updates; or a user may discover known vulnerabilities that are not corrected until the end of a long development cycle, which allows time to exploit the loopholes.

Next generation of mobile security

The following mobile environments are expected to make up future security frameworks:
; Rich operating system: This category will contain traditional mobile operating systems like Android, iOS, Symbian OS, or Windows Phone. They will provide the traditional functionality and security of an OS to the applications.
;Secure Operating System : This category features a secure kernel which will run in parallel with a fully featured Rich OS, on the same processor core. It will include drivers for the Rich OS to communicate with the secure kernel. The trusted infrastructure could include interfaces like the display or keypad to regions of PCI-E address space and memories.
;Trusted Execution Environment : This environment will be made up of hardware and software. It helps control of access rights and houses sensitive applications, which need to be isolated from the Rich OS. It effectively acts as a firewall between the "normal world" and "secure world".
; Secure Element : The SE consists of tamper-resistant hardware and associated software or separate isolated hardware. It can provide high levels of security and work in tandem with the TEE. The SE will be mandatory for hosting proximity payment applications or official electronic signatures. SE may connect, disconnect, block peripheral devices, and operate separate set of hardware.
; Security Applications : Numerous security applications are available on app stores, providing protection from viruses and performing vulnerability assessment.

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