Attackers are increasingly targeting users through their mobile devices, attacking vulnerabilities in services that are built into applications and mounting increasing numbers of SMS phishing attacks.
That's according to mobile security firm Zimperium's 2023 "Global Mobile Threat Report," which also found that the average number of unique mobile malware samples grew 51% in 2022, totaling an average of 77,000 unique malware samples found every month. About a quarter of application samples submitted to public repositories — 23% of Android apps and 24% of iOS apps — were malicious, according to data in the report.
In total, that all contributed to the number of compromised devices nearly tripling (up 187%) in the time period, because the tactics are working: The company saw an average of four malicious phishing links clicked per device, for instance.
The trend comes as companies and their workers rely increasingly on mobile devices, with a majority of firms seeing more workers (58%) using mobile devices for business than in 2021 and most users (59%) doing more work with their mobile devices, according to the 2022 "Verizon Mobile Security Index" report.
"Businesses and users need to mostly be concerned about mobile phishing and spyware today, and mobile ransomware will become increasingly concerning in the near future," says JT Keating, senior vice president of strategic initiatives at Zimperium.
Android, iOS Devices See Different Levels of Cyber Threats
About 80% of phishing sites specifically target mobile devices with content suited to those platforms, Zimperium stated in its 2023 "Global Mobile Threat Report." But, as has been the case for many years, the Android platform tends to attract more threats. One of the reasons for that could be that the Android operating system has seen between about 500 and 900 vulnerabilities disclosed per year that threat actors can target; iOS meanwhile saw a little more than 300 vulnerabilities in five of the last eight years, according to Zimperium.
Another reason that Android is a bigger target? App development mistakes. The firm found that there are more mistakes made in the process of developing apps when it comes to Android, particularly when it comes to how those apps interact with cloud storage instances. Only about 2% of iOS applications access unprotected cloud instances, while 10% of Android apps do so. These include database instances accessed through Google Firebase and Cloud Platform, Amazon Simple Storage Service (S3), and Microsoft Azure Cloud Storage, according to Zimperium's report. As a corollary, developers also tend to access the same poor resources, too: Only 1% of unprotected cloud instances accounted for 60% of applications at risk, the company said.
Georgy Kucherin, a security expert at Kaspersky's Global Research and Analysis Team (GReAT), says his firm's research bears out the finding that Android attracts more overall threats, though he notes that when it comes to spyware the targeting is evenly split between the two ecosystems; the recent Triangulation cyber espionage campaign for instance shows the value in targeting the iOS platform.
"Mobile users should worry about both cybercrime threats and nation-state espionage, [but] it is correct to say that Android faces more general threats," he says. "Android devices are more likely to become infected with malware distributed by cybercriminals. As for top-notch espionage spyware, both iOS and Android are vulnerable to it."
The lack of jailbreaking utilities for the latest version of iOS is also lowering the number of attacks for that platform, according to Zimperium. Jailbreaking allows users to add non-Apple-sanctioned software to their mobile devices, but it also removes significant security guardrails in the process.
Threats Up, or Leveling Off?
In terms of the types of mobile malware that's circulating out there, Kaspersky saw fewer mobile malware installers and less ransomware in the past year, but more banking Trojans, it stated in "The Mobile Malware Threat Landscape in 2022" report.
"Cybercriminals are still working on improving both malware functionality and spread vectors," according to the report. "Malware is increasingly spreading through legitimate channels, such as official marketplaces and ads in popular apps. This is true for both scam apps and dangerous mobile banking malware."
To put all of this into perspective, it should be noted that traditional computing platforms still attract the lion's share of the cybercrime pie. Kaspersky, for example, blocked more than 20 million malicious installers, spyware, and adware attacks on mobile devices over the last four quarters, but blocked more than 20 times that number against more common work platforms, such as Windows. However, the mobile threat vector is not as well protected.
"In most cases, mobile devices represent a significant, unaddressed attack surface for enterprises," Zimperium's Keating says. "No matter if they are corporate-owned or part of a BYOD strategy, the need to implement appropriate security controls, and educate end-users about potential threats, is critical."