Medusa Stealer

Rule Signatures
1

Hi!
I would like to share the rule on Medusa Stealer. The rule is simple but effective - 36 bytes of content containing the “chromium_browsers” encoding substring does not require padding.
I track this threat, if they change the custom protocol scheme, I will come for an update.

alert tcp any any -> any any (msg: "ET MALWARE [ANY.RUN] Medusa Stealer Exfiltration";flow: established, to_server; stream_size: server, =, 1; content: "ewogICAgImNocm9taXVtX2Jyb3dzZXJzIjog";depth: 36; classtype: credential-theft; reference:md5,6c2283c27a3ac1164aad01f982f17db3; reference:url,app.any.run/tasks/cf27f0ec-1be0-4353-82fc-d392eaa8b24b; metadata: attack_target Client_Endpoint, deployment Perimeter, former_category MALWARE, signature_severity Major, malware_family MedusaStealer, created_at 2023_06_17; sid: 8000209; rev: 1;)

Initially, it was not clear what it was, but @g0njxa helped me figure it out, thanks to him!

Best regards, Jane)

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2

Thanks @Jane0sint !! This signature will go out in today’s release!

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3

Here is the production sid/name :fire:
2046303 -[ANY.RUN] Medusa Stealer Exfiltration

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4

Hello, the @AnFam17 came out with a material about this stealer

And now, I think, it’s time to change it to a Meduza :tipping_hand_woman:

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5

Naming update will go out today :+1:

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