Detection rules › Sigma

PUA - Ngrok Execution

Severity
high
Author
Florian Roth (Nextron Systems)
Source
upstream

Detects the use of Ngrok, a utility used for port forwarding and tunneling, often used by threat actors to make local protected services publicly available. Involved domains are bin.equinox.io for download and *.ngrok.io for connections.

MITRE ATT&CK coverage

TacticTechniques
Command & ControlT1572 Protocol Tunneling

Event coverage

ProviderEvent IDTitle
Sysmon1Process creation
Security-Auditing4688A new process has been created.

Stages and Predicates

Stage 1: 1 of selection1

or:
CommandLine|contains: ' tcp 139'
CommandLine|contains: ' tcp 3389'
CommandLine|contains: ' tcp 445'
CommandLine|contains: ' tcp 5985'
CommandLine|contains: ' tcp 5986'

Stage 2: 1 of selection2

CommandLine|contains: ' start '
CommandLine|contains: --all
CommandLine|contains: --config
CommandLine|contains: .yml

Stage 3: 1 of selection3

or:
CommandLine|contains: ' authtoken '
CommandLine|contains: ' http '
CommandLine|contains: ' tcp '
Image|endswith: ngrok.exe

Stage 4: 1 of selection4

or:
CommandLine|contains: '.exe authtoken '
CommandLine|contains: '.exe start --all'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
CommandLinematch
  • authtoken
  • http
  • start corpus 2 (sigma 2)
  • tcp
  • tcp 139
  • tcp 3389
  • tcp 445
  • tcp 5985
  • tcp 5986
  • --all
  • --config
  • .exe authtoken
  • .exe start --all
  • .yml corpus 2 (sigma 2)
Imageends_with
  • ngrok.exe