Batchwiper: How I Learned to Worry Less and Love Least Privilege Security

With news coming from Iran’s CERT of a nasty (but not really nasty) new piece of malware designed to wipe drives and desktop contents on a specific date, we took the straightforward approach of examining what common, easily implemented security best practices could have stopped Batchwiper in its tracks… As far as malware goes, Batchwiper is very rudimentary in its execution and capabilities, yet it still has the capacity to cause damage – so how might someone defend themselves from Batchwiper? Simple: run with least privileges. Running as non-administrator effectively neutralizes the dropper component of Batchwiper, specifically GrooveMonitor.exe (MD5 - f3dd76477e16e26571f8c64a7fd4a97b). The dropper is a self-extracting archive, which attempts to put files in the WINDOWSsystem32 folder. If you’re running as non-admin, the dropper has no permissions to write to that location and the malware will simply fail to execute its intended payloads. [caption id="attachment_13919" align="aligncenter" width="530"] Least privilege defeats Batchwiper dropper.[/caption] If you are unfortunate enough to have a corporate IT environment that does not properly manage Administrative privileges, then the dropper will continue to execute by spawning a series of processes. This eventually leads to Batchwiper formatting drives D through I, performing a Disk Check on each drive (possibly to mask the cause of the data loss), and then deleting the current user profile’s desktop contents. [caption id="attachment_13920" align="aligncenter" width="827"] Batchwiper processes spawned by dropper.[/caption] This malware serves as another example in a long line of threats that are, in most cases, completely (if not severely) mitigated by good security configuration best practices such as practicing Least Privilege. BeyondTrust has been at the forefront of championing the cause of Least Privilege for quite some time through our BeyondTrust PowerBroker solutions for both Windows and Unix/Linux. Customers leveraging BeyondTrust’s PowerBroker for Windows will mitigate a large majority of malware that affects companies on a day-to-day basis, including this recent Batchwiper malware. You can find out more about our Least Privilege solutions here: https://www.beyondtrust.com/Products/PowerBrokerForWindows/