We investigated a case where an email sent the victim to a MediaFire ZIP. We have not observed this exact chain as part of a broader campaign so far, but there are a lot of things from this that wanted to share which worth a closer look.
𝗘𝘅𝗲𝗰𝘂𝘁𝗶𝗼𝗻 𝗰𝗵𝗮𝗶𝗻 (𝘀𝗲𝗲 𝗮𝘁𝘁𝗮𝗰𝗵𝗲𝗱 𝗶𝗺𝗮𝗴𝗲)
𝗜𝗻𝘀𝗶𝗱𝗲 𝘁𝗵𝗲 𝗲𝘅𝘁𝗿𝗮𝗰𝘁𝗲𝗱 𝘀𝗲𝘁𝘂𝗽 𝗳𝗼𝗹𝗱𝗲𝗿:
• 𝚂𝚎𝚝𝚞.𝚎𝚡𝚎 was a Python setup executable
• VMware utilities were present but not observed being used
• 𝚙𝚢𝚝𝚑𝚘𝚗𝟹𝟽.𝚍𝚕𝚕 was the malicious outlier with a nearly 400 MB size
• Hex review showed repeated 𝙹 byte padding on that malicious DLL, hence the size
• The DLL was side-loaded by 𝚂𝚎𝚝𝚞.𝚎𝚡𝚎
• We also observed process injection to dllhost.exe which reached out to the first C2: 138[.]124[.]186[.]2:7000 (see attached image for network traffic details)
By the end, the actor had:
- One PowerShell-based path
- One fake EdgeUpdate Python path scheduled task for persistence
- One NetSupport RMM path
NetSupport was the third access method, added after two other C2 paths were already present.
𝘋𝘍𝘐𝘙 𝘯𝘰𝘵𝘦: 𝘸𝘩𝘦𝘯 𝘳𝘦𝘷𝘪𝘦𝘸𝘪𝘯𝘨 𝘥𝘳𝘰𝘱𝘱𝘦𝘥 𝘢𝘳𝘵𝘪𝘧𝘢𝘤𝘵𝘴 𝘧𝘳𝘰𝘮 𝘢 𝘡𝘐𝘗, 𝘤𝘰𝘮𝘱𝘢𝘳𝘦 𝘮𝘰𝘥𝘪𝘧𝘪𝘦𝘥 𝘥𝘢𝘵𝘦𝘴 𝘢𝘤𝘳𝘰𝘴𝘴 𝘧𝘪𝘭𝘦𝘴 𝘢𝘯𝘥 𝘥𝘪𝘳𝘦𝘤𝘵𝘰𝘳𝘪𝘦𝘴. 𝘐𝘯 𝘵𝘩𝘪𝘴 𝘤𝘢𝘴𝘦, 𝘵𝘪𝘮𝘦𝘴𝘵𝘢𝘮𝘱 𝘥𝘪𝘧𝘧𝘦𝘳𝘦𝘯𝘤𝘦𝘴 𝘩𝘦𝘭𝘱𝘦𝘥 𝘩𝘪𝘨𝘩𝘭𝘪𝘨𝘩𝘵 𝘸𝘩𝘪𝘤𝘩 𝘢𝘳𝘵𝘪𝘧𝘢𝘤𝘵 𝘥𝘦𝘴𝘦𝘳𝘷𝘦𝘥 𝘢𝘵𝘵𝘦𝘯𝘵𝘪𝘰𝘯 𝘧𝘪𝘳𝘴𝘵. 𝘘𝘶𝘪𝘤𝘬 𝘸𝘪𝘯 𝘥𝘶𝘳𝘪𝘯𝘨 𝘵𝘳𝘪𝘢𝘨𝘦.
𝗜𝗢𝗖𝘀
• hxxps://pub-2f1bcdf12a2e44408e7a58efe6006d43[.]r2[.]dev/LICENSES.chromium.dat
• pub-2f1bcdf12a2e44408e7a58efe6006d43[.]r2[.]dev
• bsc[.]blockrazor[.]xyz
• mgo[.]gstats-api-contact[.]cc
• xn--fiqq24b9hejs1c[.]clickvector[.]tech
• 138[.]124[.]186[.]2:7000
• 185[.]76[.]243[.]85:443
• %LOCALAPPDATA%\Microsoft\EdgeUpdate\{GUID}\1.3.467.47\pythonw.exe
• NetSupport RMM: %APPDATA%\Microsoft\Image\SQLTool\46a05ef1a89e0c8a\century.exe
• MicrosoftEdgeUpdateTaskUserUA{GUID}-<SID suffix>
We share these public notes so defenders can hunt faster and protect their environments. For teams that need the full context, our enterprise threat intel feed includes the detailed commands, timeline reconstruction, artifacts, and detection leads behind cases like this. Reach out to
threathuntinglabs.com/contac… for more info.