Researchers analyzed a sample of the MegaCortex ransomware family that used an aggressive ransom note to bully victims into meeting their demands.
In its analysis, Bleeping Computer observed that someone had signed the code for the MegaCortex ransomware sample using a certificate that belonged to a U.K. company named ABADAN PIZZA LTD. The computer security website also noted that the sample no longer required a base64 encoded string to unpack the threat’s Dynamic Link Library (DLL) payload and inject it into memory. Instead, the researchers found it was possible to simply run the executable and then begin encrypting an infected computer’s files.
Following execution, the ransomware displayed an output of processed files and its current stage of operation. Bleeping Computer interpreted this step as a means to help digital attackers monitor the threat’s activity. From there, the sample terminated more than a thousand Windows services and processes before launching its encryption routine and appending .megacortex to every file it encrypted.
It finished by displaying a ransom note from attackers with comparatively more aggressive language than other ransomware messages, informing victims to not “waste our and your time” and to remember that the malware’s handlers “don’t do charity.”
Standing Out in the Ransomware Landscape
First detected by Sophos in May 2019, MegaCortex quickly built a name for itself by targeting enterprise networks consisting of hundreds of machines using both automated and manual components. In doing so, it joined other ransomware families that distinguished themselves in the first half of 2019.
For instance, Acronis noted how the RobbinHood family gained notoriety by mainly going after the computer systems of U.S. municipalities. It wasn’t long after that Anomali Labs uncovered eCh0raix, ransomware that at one point developed a habit of targeting QNAP Network Attached Storage (NAS) devices.
How to Defend Against MegaCortex
Security professionals can help defend their organizations against MegaCortex by integrating their security information and event management (SIEM), incident response, endpoint detection and response (EDR), and other network security solutions together to comprehensively watch out for network attacks and thereby protect the business against sophisticated ransomware. Companies should also focus on user education to prevent ransomware from making its way onto the network via spear-phishing emails and other social engineering attacks.