I've been reading about "wiper" attacks and APTs that deploy ransomware not for money, but to cover their tracks after exfiltrating data. How can an incident response team distinguish between a standard financially motivated ransomware attack and a deep-seated APT that is just using encryption as a smoke screen to hide their presence?
3 answers
Check your firewall logs for long-running outbound SSH or HTTPS connections that started weeks ago. These are your C2 channels.
Are you analyzing the ransomware code itself to see if it’s a "leaked" builder used by many, or a custom-written piece of malware unique to one group?
Brandon, we found that the code was a modified version of LockBit, which made it confusing. However, Michelle's point about data staging was the "aha!" moment for us. We found a hidden directory on a file server containing compressed backups of our R&D database that were created three days before the "ransomware" even touched the network. This confirms it was a distraction. We're now shifting our focus from just restoring files to a full-blown hunt for the backdoors they likely left behind to maintain access post-remediation.
The key is the "dwell time" and the sequence of events. In a standard ransomware attack, the time between entry and encryption is usually short. In an APT scenario, the encryption happens after weeks of lateral movement and data staging. During your forensic investigation, look for signs of data archival (like large .7z or .rar files in Temp folders) and external transfers via tools like Rclone or MegaSync prior to the ransomware execution. If you find evidence of massive outbound traffic to a cloud storage provider right before the systems went dark, you aren't dealing with a simple hacker; you're dealing with an exfiltration-first APT.
Absolutely, Robin. Those persistent "heartbeat" connections are the smoking gun. Finding them is the only way to ensure the threat actor is truly gone.