Japanese users were flooded with BEBLOH and URSNIF malware infections last month via spam campaigns that exploited internet query (IQY) files.

Much like traditional approaches to social engineering, the cybercriminals behind the attacks attempted to fool users with a variety of calls to open an email attachment, Trend Micro reported in late August. This included requests such as “please confirm,” “photos attached” and even “payment.” According to the researchers, the spam campaigns, which began on Aug. 6 and appeared to die down as of Aug. 10, involved an estimated 500,000 messages.

While URSNIF is best known for monitoring browser sessions and stealing data, BEBLOH is a banking Trojan that has been active in Japan since 2016.

Why IQY Attacks Are Basic by Design

When victims downloaded the attachment, it triggered an IQY file that sent a request to a specific URL. At the same time, it also exploited Excel’s Dynamic Data Exchange (DDE) feature with a script that used PowerShell to confirm that the machine’s IP address was based in Japan. If confirmed, the payload containing BEBLOH or URSNIF malware was executed.

IQY files are not necessarily complex, and that’s the point. Security researchers said the basic composition of IQY files makes it easier for cybercriminals to avoid detection by more traditional, structure-based ways of uncovering security threats.

How to Prepare for IQY Attacks and Spam Campaigns

Research has shown that the use of IQY files for nefarious purposes may be on the rise. IBM X-Force has been tracking similar activity to spread malware via the Necurs botnet, for example.

While IP address whitelisting and email filtering may help to some extent, IBM experts recommend using a security information and event management (SIEM) solution to help identify IQY-based threats early on. Security leaders should also train employees about the risks associated with IQY files and how they can be used in spam campaigns.

Source: Trend Micro

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