101. Gamaredon Hides C&C Server Address Under the Registry

Hello everyone! In some case you can find a C&C server address under not so common places. For example, Windows registry.

If we look through this report on Gamaredon's GammaSteel, we can see that the adversary does just this:

IWshShell3.RegWrite("HKEY_CURRENT_USER\Console\WindowsUpdates", "http://172.104.187.254/mood/1/3/2025/confer.html?=[REMOVED]", "REG_SZ");

As you can see, it uses "HKEY_CURRENT_USER\Console\WindowsUpdates" to store the C&C adress. It means we can search for its modifiction events:

event_type: "registryvalueset"

AND

reg_key_path: "Console\\WindowsUpdates"

Of course, this approach won't allow you to detect similar activity for a long time, so you can experiment with variations of key names as well as hunt for adding URLs to various registry keys.

See you tomorrow!

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