Attacks spreading the Remcos RAT malware have been launched by Russian state-backed cyberespionage operation Gamaredon against Ukraine as part of a phishing campaign that has been underway since November, reports Security Affairs.
Gamaredon, also known as ACTINIUM, Armageddon, Callisto, and Primitive Bear, distributes phishing emails using troop-related lures that include malicious LNK files containing PowerShell code, which facilitates second-stage payload and decoy file deployment to evade detection, according to an analysis from Cisco Talos. Extraction of the payload to the %TEMP% folder is then followed by side-loading of another DLL that loads, decrypts, and executes Remcos RAT. Further analysis of Gamaredon's PowerShell scripts indicates legitimate app exploitation and the utilization of clean and malicious files, said Cisco Talos researchers. "We can see in the previously mentioned sample downloaded by "Any.run" that it contains the clean application TivoDiag.exe, as well as two DLLs. The file "mindclient.dll" is the malicious DLL which is loaded by "TivoDiag.exe" during execution," the report noted.
