Detection rules › Sigma

Network share discovery and/or connection via commandline

Severity
high
Log source
product windows, category process_creation
Author
mdecrevoisier
Source
github.com/mdecrevoisier/SIGMA-detection-rules

Detects scenarios where an attacker attempts to enumerate or to establish a connection to a network share.

MITRE ATT&CK coverage

TacticTechniques
DiscoveryT1135 Network Share Discovery

Event coverage

Rule body yaml

title: Network share discovery and/or connection via commandline
description: Detects scenarios where an attacker attempts to enumerate or to establish a connection to a network share.
references:
- https://github.com/mdecrevoisier/EVTX-to-MITRE-Attack/tree/master/TA0007-Discovery/T1135.xxx-Network%20Share%20Discovery
- https://blogs.jpcert.or.jp/en/2016/01/windows-commands-abused-by-attackers.html
- https://attack.mitre.org/software/S0039/
tags:
- attack.discovery
- attack.t1135
author: mdecrevoisier
logsource:
  product: windows
  category: process_creation
detection:
  selection:
    NewProcessName|endswith:
      - \net1.exe
      - \net.exe
    CommandLine|contains:
      - net view # view external shares in the network
      - net use  # view current mapped network shares
  condition: selection
falsepositives:
- Pentest
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
  NewProcessName|endswith:
    - \net1.exe
    - \net.exe
  CommandLine|contains:
    - net view
    - net use

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
  • net use corpus 2 (sigma 2)
  • net view
NewProcessNameends_with
  • \net.exe corpus 49 (sigma 49)
  • \net1.exe corpus 47 (sigma 47)