""ET TROJAN Win32/nstealer CnC Exfiltration (POST) M2""

SID: 2048230

Revision: 1

Class Type: trojan-activity

Metadata: affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2023_09_25, deployment Perimeter, deployment SSLDecrypt, malware_family Nstealer, confidence High, signature_severity Critical, updated_at 2023_09_25, reviewed_at 2023_09_25

Reference:

Protocol: tcp

Source Network: $HOME_NET

Source Port: any

Destination Network: $EXTERNAL_NET

Destination Port: $HTTP_PORTS

Flow: established,to_server

Contents:

  • Value: "POST"

  • Value: "filename|3d 22|US|5b|"

  • Value: "|2e|zip|22 0d 0a|"

  • Value: "|0d 0a 0d 0a 50 4b|"

  • Value: "filename|3d 22|US|5b|"

  • Value: "|2f|Autofills|2f 50 4b|"

  • Value: "|2f|InstalledSoftware|2e|txt"

Within:

PCRE: "/^(?:[0-9A-Z]{32})/R"

Special Options:

  • http_method

  • http_client_body

  • http_client_body

  • http_client_body

  • http_client_body

  • http_client_body

  • fast_pattern

  • http_client_body

source