As user habits evolve, so do the tactics of attackers. It should come as little surprise then that as enterprises upgraded to newer versions of Windows in 2014, the amount of 64-bit Windows malware being used in attack campaigns increased as well.
According to researchers at Trend Micro, this is just one example of how targeted attacks are evolving with the times.
“The move to newer versions of Windows also led to the abuse of legitimate tools/features in attacks,” Trend Micro noted in a blog post. “An example is Windows PowerShell, a feature in versions for Windows 7 and higher that allows system administrators to access other features without the use of graphical user interfaces (GUIs). PowerShell commands were abused to download malicious files and bypass execution policies, which allowed the downloaded files to be executed.”
Trend Micro outlines a series of changes in the tactics being used by cybercriminals in a new report entitled, ‘TrendLabs 2014 Targeted Attack Campaign Report.’ Among the changes are improvements to command and control and lateral movement techniques. For example, in a targeted attack against a Taiwanese government agency, the attackers used a PlugX RAT variant that allowed them to use Dropbox as a drop zone to evade detection.
“Attackers used different methods to access and encrypt communications,” the report notes. “They did not need to infect Internet-connected hosts for C&C; they instead used parallel infected hosts. They also employed commercial and public virtual private networks (VPNs) for C&C. Tor was typically leveraged to hide malicious network traffic and maintain persistence in target networks. BIFROSE variants often sported such routines, particularly BKDR_BIFROSE.ZTBG-A, which used Tor for C&C.20.”
Based on Trend Micro’s data, .RTF and .DOC files were the two most frequently used email attachments in targeted attacks last year, which the firm speculates is due to the popularity of Microsoft Word. Attackers used a mix of zero-day exploits and known vulnerabilities to infect their targets. For example, two Taidoor-related zero-day exploit attacks targeting CVE-2014-1761 hit government agencies and an educational institution in Taiwan and had a window of exposure of 15 days.
However, older vulnerabilities remained in vogue. CVE-2012-0158 for example was a favorite of attackers, and was the most exploited vulnerability used in targeted attacks in the first half of 2014, Trend Micro reported.
“Government agencies remained the most favored attack targets in 2014,” Trend Micro blogged. “In the second half of the year, we saw a spike in the number of attacks that targeted hardware/software companies, consumer electronics manufacturers, and health care providers.”
The full report can be read here.