A new worm for Windows computers is spreading fast, Microsoft is warning IT security pros, but so far no attacker has taken advantage of the infections.
According to the Bleeping Computer news service, Microsoft has sent out an alert about the hazard in a private threat intelligence advisory to Microsoft Defender for Endpoint subscribers.
Dubbed Raspberry Robin, it’s been spreading via infected USB devices that have a malicious .LNK file masquerading as a legitimate folder on the infected device. When victims click on the file or folder, the infection chain starts.
One of the first defences, therefore, is to warn employees of the dangers of plugging in USB keys from unknown sources, including colleagues, friends, and devices found lying on the floor.
What’s alarming is it can bypass User Account Control (UAC) on infected systems using legitimate Windows tools.
The worm was first identified in May by researchers at Red Canary. It leverages Windows Installer to reach out to compromised QNAP storage devices and download a malicious DLL. It can also use TOR exit nodes as additional command and control (C2) infrastructure.
There are a number of unanswered questions about the worm, say Red Canary researchers. That includes how or where external drives are infected, or why it installs a malicious DLL. One hypothesis is that may be an attempt to establish persistence on an infected system.
“Perhaps our biggest question concerns the operators’ objectives,” they add. “Absent additional information on later-stage activity, it’s difficult to make inferences on the goal or goals of these campaigns.”