Detection rules › Sigma

Security Tools Keyword Lookup Via Findstr.EXE

Severity
medium
Author
Nasreddine Bencherchali (Nextron Systems), frack113
Source
upstream

Detects execution of "findstr" to search for common names of security tools. Attackers often pipe the results of recon commands such as "tasklist" or "whoami" to "findstr" in order to filter out the results. This detection focuses on the keywords that the attacker might use as a filter.

MITRE ATT&CK coverage

TacticTechniques
DiscoveryT1518.001 Software Discovery: Security Software Discovery

Event coverage

ProviderEvent IDTitle
Sysmon1Process creation

Stages and Predicates

Stage 1: all of selection_img

or:
Image|endswith: '\find.exe'
Image|endswith: '\findstr.exe'
OriginalFileName: FIND.EXE
OriginalFileName: FINDSTR.EXE

Stage 2: all of selection_cli

or:
CommandLine|endswith: ' avira'
CommandLine|endswith: ' avira"'
CommandLine|endswith: ' cb'
CommandLine|endswith: ' cb"'
CommandLine|endswith: ' cylance'
CommandLine|endswith: ' cylance"'
CommandLine|endswith: ' defender'
CommandLine|endswith: ' defender"'
CommandLine|endswith: ' kaspersky'
CommandLine|endswith: ' kaspersky"'
CommandLine|endswith: ' kes'
CommandLine|endswith: ' kes"'
CommandLine|endswith: ' mc'
CommandLine|endswith: ' mc"'
CommandLine|endswith: ' sec'
CommandLine|endswith: ' sec"'
CommandLine|endswith: ' sentinel'
CommandLine|endswith: ' sentinel"'
CommandLine|endswith: ' symantec'
CommandLine|endswith: ' symantec"'
CommandLine|endswith: ' virus'
CommandLine|endswith: ' virus"'

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
CommandLineends_with
  • avira
  • avira"
  • cb
  • cb"
  • cylance
  • cylance"
  • defender
  • defender"
  • kaspersky
  • kaspersky"
  • kes
  • kes"
  • mc
  • mc"
  • sec
  • sec"
  • sentinel
  • sentinel"
  • symantec
  • symantec"
  • virus
  • virus"
Imageends_with
  • \find.exe corpus 8 (sigma 8)
  • \findstr.exe corpus 11 (sigma 11)
OriginalFileNameeq
  • FIND.EXE corpus 6 (sigma 6)
  • FINDSTR.EXE corpus 10 (sigma 10)