The Lockergoga ransomware encrypts all the files in the system and appends .locked extension and leaves a ransom note in the desktop folder. It was written in C++ with the helper libraries such as Boost and Crypto++.
Now an Alert Logic researchers discovered a bug in the ransomware that halts the infection process in the initial reconnaissance stage itself.
Once the ransomware enters into the system it scans to gather file lists before it starts the encryption process.
When it encounters a ‘.lnk’ file it will utilize the built-in shell32 / linkinfo DLLs to resolve the ‘.lnk’ path. However, if this ‘.lnk’ path has one of a series of errors then malware encounters an unhandled exception it is terminated by the operating system, reads Alert Logic blog post.
In this scenario, the ransomware halts its process in the reconnaissance phase itself and no encryption will happen.
Alert Logic identified two conditions for the ‘.lnk’ file which could halt the ransomware progress.
The ‘.lnk’ file has been crafted to contain an invalid network path
The ‘.lnk’ file has no associated RPC endpoint.
Crafting a malformed ‘.lnk’ file is the best preventive method to stop the Lockergoga Ransomware infection.
LockerGoga looks for following file types to encrypt,
.doc, .dot, .docx, .docb, .dotx, .wkb, .xlm, .xml, .xls, .xlsx, .xlt, .xltx, .xlsb, .xlw, .ppt, .pps, .pot, .ppsx, .pptx, .posx, .potx, .sldx, .pdf, .db, .sql, .cs, .ts, .js, .py.
Related Read:Ransomware Attack Response and Mitigation Checklist