Recently, a mass stabbing incident in Kunming, China left 29 victims dead. We came across an email which used this incident as social engineering bait. To appear legitimate, the message talks about the incident at length and cites several news outlets as its sources. It encourages the user to open the attached document for more information. The document is entitled “Violent terror attack,” probably named as such to pique the recipient’s interest.
Figure 1. Spammed message
The attached document is actually malicious, and is detected as TROJ_EXPLOYT.AGH. This malware takes advantage of a particular Microsoft Office vulnerability (CVE-2012-0158, or MS12-027) to drop a backdoor – BKDR_GHOST.LRK - onto the system. Apart for its backdoor routines, this malware can steal information through keylogging, audio recording, and screen capture.
A closer look into BKDR_GHOST.LRK reveals one striking detail: when it communicates to its C&C server, the malware uses the string “LURK0″. This string was also associated with a malware variant that was used in the GhostNet campaign. We noted in a previous paper titled Detecting APT Activity with Network Traffic Analysis that a Ghost variant had replaced “Gh0st” (its usual header content) with “LURK0″.
The configuration file also contains the marker “default.” This is often used as a mark on which campaign a malware belongs to. However, Trend Micro researchers have encountered old samples bearing the same markers dating back to 2012.
Despite its intended target, regular users can still find themselves victims of this attack. Email attacks often use “click-worthy” or interesting topics to convince users to click links or open attachments that could lead to various threats.
Users are advised to avoid opening attachments and click links on unsolicited emails. They should also visit reputable and trustworthy news sites for updates on the latest news and current events. We detect and block all threats related to this incident.
Additional analysis by Mark Manahan.