146. Adversaries Abuse Haihaisoft PDF Reader to Deliver Rhadamanthys Stealer

Hello everyone!

As you know, stealers are the most common threats nowadays. What does it mean? Threat actors find new and new ways to deliver it to the target system.

Let's look at Rhadamanthys campaign uncovered by Cybereason. The adversary abused a renamed Haihaisoft PDF Reader executable (for example, Preuve de la violation.pdf .exe) to sideload a malicious DLL (msimg32.dll), which which enabled persistence and downloaded the stealer payload.

As we're dealing with a renamed exacutable, we can use it to build our detection logic:

event_type: "processcreatewin"

AND

proc_file_originalfilename: "hpreader.exe"

AND NOT

proc_file_name: "hpreader.exe"

See you tomorrow!

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