""ET SCAN MS Terminal Server Traffic on Non-standard Port""

SID: 2023753

Revision: 3

Class Type: attempted-recon

Metadata: affected_product Microsoft_Terminal_Server_RDP, attack_target Server, created_at 2017_01_23, deployment Perimeter, performance_impact Moderate, signature_severity Major, updated_at 2022_09_14

Reference:

Protocol: tcp

Source Network: $EXTERNAL_NET

Source Port: any

Destination Network: $HOME_NET

Destination Port: !3389

Flow: to_server,established

Contents:

  • Value: "|03 00 00|" Depth: 3

  • Value: "|e0 00 00 00 00 00|" Depth: 6 Offset: 5

  • Value: "Cookie|3a 20|mstshash="

Within:

PCRE:

Special Options:

  • fast_pattern

source