A Zeek Based AsyncRAT Malware Detector
Malware often hides communications with its command and control (C2) server over HTTPS. The encryption in HTTPS usually conceals the compromise long enough for the malware to accomplish its goal. This makes detecting malware that uses HTTPS challenging, but once in a while, you will catch a break, as in the case here with AsyncRAT, a Windows remote access tool that has been deployed over the past year to target organizations that manage critical infrastructure in the United States.
Example Notice.log Output
#separator \x09
#set_separator ,
#empty_field (empty)
#unset_field -
#path notice
#open 2024-03-12-13-19-10
#fields ts uid id.orig_h id.orig_p id.resp_h id.resp_p fuid file_mime_type file_desc proto note msg sub src dst p n peer_descr actions email_dest suppress_for remote_location.country_code remote_location.region remote_location.city remote_location.latitude remote_location.longitude
#types time string addr port addr port string string string enum enum string string addr addr port count string set[enum] set[string] interval string string string double double
1709051041.876652 CLNN1k2QMum1aexUK7 192.168.100.124 49207 181.131.218.39 4041 - - - tcp AsyncRAT::C2_Traffic_Observed Potential AsyncRAT C2 discovered via a default SSL certificate. Cert Fingerprints: [ce772ec37d88351f43e6350c6c2b9777c9a7855f2a55184fba784e5e7df9e3eb] Issuer: CN=AsyncRAT Server 192.168.100.124 181.131.218.39 4041 - - Notice::ACTION_LOG (empty) 3600.000000 - - - - -
#close 2024-03-12-13-19-10
Suricata Rules
You can find Suricata rules in the "suri" directory.
PCAP Sources
- AsyncRAT
- DcRat By qwqdanchun
- SXN Server