The number of mobile malware attacks detected in 2017 has increased to 42.7 million, according to a new report from Kaspersky Lab.
The surge in attacks was in contradiction to evolution of detected mobile malicious installation packages, which amounted to 5,730,916 in 2017, almost 1.5 times lower than 2016.
The number of attacked users, however, increased 1.2 times compared to the previous year. According to Kaspersky, they protected 4,909,900 unique users of Android devices from the beginning of January until the end of December 2017.
The Moscow-based security firm also says that it detected 94,368 mobile banking Trojans in 2017, 1.3 times less than in the previous year. This type of malware attacked 259,828 users in 164 countries, with Russia, Australia, and Turkey being hit the most.
544,107 mobile ransomware Trojans were detected last year, twice as much as in 2016 and 17 times more than in 2015. Ransomware hit 110,184 Android users in 161 countries, with the United States, Kazakhstan and Belgium being hit the most.
The number of users attacked by rooting malware decreased last year, yet this type of malware continued to be popular, accounting for nearly half of the Trojans in the company’s Top 20 list. Such malware usually attempts to gain super-user rights by exploiting system vulnerabilities.
Their decline in popularity among cybercriminals can be explained mainly by the decline in the number of devices still running older Android versions. Android 5.0 or older was found on 57% of the devices in 2017, while Android 6.0 or newer doubled in 2017 compared to 2016.
“Newer versions of Android don’t yet have common vulnerabilities that allow super-user rights to be gained, which is disrupting the activity of rooting malware,” Kaspersky notes.
Despite that, rooting malware continues to be a major threat to Android users, as they are difficult to detect and pack a variety of capabilities. Rooting malware installs modules in system folders to ensure persistency and can sometimes even resist a reset to factory settings.
Notable mentions in the rooting malware category include Ztorg, which infected 100 apps in Google Play and was downloaded tens of thousands of times, and Dvmap, which was downloaded over 50,000 times from the official application store.
In 2017, Kaspersky also discovered new WAP Trojans, malware families that usually follow links received from the command and control (C&C) server and then ‘click’ on page elements using a specially created JS file. Such malware can visit regular advertising sites or pages with WAP subscriptions.
Mobile banking malware also evolved in 2017, “offering new ways to steal money,” Kaspersky says. A modification of FakeToken, for example, was observed targeting apps for booking taxis, hotels, tickets, and the like, in addition to the usually attacked financial apps. The malware overlays the legitimate applications with its phishing windows.
While the latest Android releases attempt to prevent malware from performing malicious actions, banking Trojans last year found new ways to bypass these protections. A Svpeng variant observed last year was abusing accessibility services to grant itself some permissions such as the ability to send and receive SMSs, make calls, and read contacts, in addition to adding itself to the list of device admins to prevent removal.
Last year, both Svpeng and Faketoken “acquired modifications capable of encrypting user files,” Kaspersky reports. However, the encryptor functionality wasn’t that popular among mobile Trojans.
Mobile ransomware Trojans were highly active last year and even registered massive growth during the first half of the year, when detections were up 1.6 times than the entire 2016. Starting June, however, the activity of these malware families returned to normal.
The segment, Kaspersky says, was dominated by the Congur ransomware, with over 83% of all installation packages in 2017 belonging to this family. This simple malware changes device’s PIN code and instructs the owner to contact the attackers via the QQ messenger.
Last year, Trojan-Ransom malware experienced the highest overall growth, followed by RiskTool threats. Trojan-SMS installation packages and Trojan-Dropper malware decreased.
Overall, users in over 230 countries and territories were targeted by malware in 2017, with Iran, Bangladesh, and Indonesia emerging as the top attacked countries.