""ET TROJAN Cobalt Strike Beacon Activity""

SID: 2032360

Revision: 2

Class Type: trojan-activity

Metadata: attack_target Client_Endpoint, created_at 2021_04_01, deployment Perimeter, deployment SSLDecrypt, signature_severity Major, tag c2, updated_at 2021_04_01, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel

Reference:

• md5

• c5668ee76cb9a9a5c4837eb0049c005b

Protocol: tcp

Source Network: $HOME_NET

Source Port: any

Destination Network: $EXTERNAL_NET

Destination Port: $HTTP_PORTS

Flow: established,to_server

Contents:

• Value: "GET"

• Value: ".html?usersearch="

• Value: !"Referer|3a 20|"

Within:

PCRE: "/^reg_fb_gate=(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})$/C"

Special Options:

• http_method

• fast_pattern

• http_uri

• http_header

source