The new campaign started right after the Spanish Civil Guard announced the arrest of 16 people involved with Mekotio distribution in July 2021.
It appears that the gang behind the malware were able to narrow the gap quickly and change tactics to avoid detection.
CPR assume that the main cybercrime groups are operating from Brazil and they collaborated with Spanish gangs to distribute malwares.
The arrest stopped the activity of the Spanish gangs but not the main cybercrime groups.
Mekotio’s new infection vector contains these unprecedented elements:
A stealthier batch file with at least two layers of obfuscation.
New fileless PowerShell script that runs directly in memory.
Use of Themida v3 for packing the final DLL payload.
In the last 3 months, CPR saw approximately 100 attacks use new, simple obfuscation techniques, with the help of a substitution cipher, to hide the first module of the attack.
This simple obfuscation technique allows it to go undetected by most of the AntiVirus products.