""ET WEB_SERVER LEMURLOOT WebShell Interaction Header - X-siLock-Step2/3 File Retrieval Request- Observed in MOVEit File Transfer - INBOUND""

SID: 2046052

Revision: 1

Class Type: attempted-admin

Metadata: attack_target Web_Server, created_at 2023_06_02, deployment Perimeter, deployment SSLDecrypt, malware_family LEMURLOOT, performance_impact Low, confidence High, signature_severity Major, tag WebShell, updated_at 2023_06_02

Reference:

Protocol: tcp

Source Network: $EXTERNAL_NET

Source Port: any

Destination Network: [$HOME_NET,$HTTP_SERVERS]

Destination Port: any

Flow: established,to_server

Contents:

  • Value: "X-siLock-Comment|3a 20|"

  • Value: "X-siLock-Step2|3a 20|"

  • Value: "X-siLock-Step3|3a 20|"

Within:

PCRE:

Special Options:

  • http_header

  • http_header

  • http_header

source