Detection rules › Splunk

Security Software Discovery via Findstr.exe (Sysmon)

Group by
_time, host
Source
github.com/anvilogic-forge/armory

Threat actors may enumerate security software, configurations, and monitoring tools on a system or cloud environment to evade defenses or tailor their attack. This can involve querying registry keys, running system commands, or checking for specific processes related to security tools. This use case detects instances where findstr.exe or find.exe are executed to search for security software on the host.

MITRE ATT&CK coverage

References

Telemetry coverage

ProviderRecord / event type
SysmonEvent ID 1: Process creation

Rule body

id: '43757.85556'
title: Security Software Discovery via Findstr.exe
description: Threat actors may enumerate security software, configurations, and monitoring
  tools on a system or cloud environment to evade defenses or tailor their attack.
  This can involve querying registry keys, running system commands, or checking for
  specific processes related to security tools. This use case detects instances where
  findstr.exe or find.exe are executed to search for security software on the host.
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_sysmon` (TERM(EventCode=1) OR "<EventID>1<")
  ("findstr.exe" OR TERM(findstr) OR "find.exe" OR TERM(find)) ("avira" OR "cb" OR
  "cylance" OR "defender" OR "kaspersky" OR "kes" OR "mc" OR "sec" OR "sentinel" OR
  "symantec" OR "virus" OR "wrsa" OR "opssvc" OR "avastui" OR "avgui" OR "bdservicehost"
  OR "nsWscSvc" OR "ekrn" OR "sophoshealth" OR "falcon") | where match(process_path,
  "(?i)\x5cWindows\x5cSystem32\x5cfindstr\.exe|\x5cWindows\x5cSysWOW64\x5cfind\.exe")
  and match(process, "(?i)\w+(\.exe)?\x22?\s+(avira|cb|cylance|defender|kaspersky|kes|mc|sec|sentinel|symantec|virus|wrsa|opssvc|avastui|avgui|bdservicehost|nsWscSvc|ekrn|sophoshealth|falcon)\x22?$")
  | table _time, host, user, process, process_*, parent_* | bin span=1s | stats values(*)
  as * by _time, host '
techniques:
- discovery:software discovery:security software discovery
technique_id:
- T1518.001
data_category:
- Windows Sysmon
references:
- https://attack.mitre.org/techniques/T1518/001/
- https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/findstr
- https://github.com/redcanaryco/atomic-red-team/blob/987e3ca988ae3cff4b9f6e388c139c05bf44bbb8/atomics/T1518.001/T1518.001.md#atomic-test-1---security-software-discovery
- https://www.microsoft.com/en-us/security/blog/2025/03/06/malvertising-campaign-leads-to-info-stealers-hosted-on-github/
- https://detection.fyi/sigmahq/sigma/windows/process_creation/proc_creation_win_findstr_security_keyword_lookup/

Stages and Predicates

Stage 1: search

`get_endpoint_data` `get_endpoint_data_sysmon` (TERM(EventCode=1) OR "<EventID>1<") ("findstr.exe" OR TERM(findstr) OR "find.exe" OR TERM(find)) ("avira" OR "cb" OR "cylance" OR "defender" OR "kaspersky" OR "kes" OR "mc" OR "sec" OR "sentinel" OR "symantec" OR "virus" OR "wrsa" OR "opssvc" OR "avastui" OR "avgui" OR "bdservicehost" OR "nsWscSvc" OR "ekrn" OR "sophoshealth" OR "falcon")

Stage 2: where

| where match(process_path, "(?i)\x5cWindows\x5cSystem32\x5cfindstr\.exe|\x5cWindows\x5cSysWOW64\x5cfind\.exe") and match(process, "(?i)\w+(\.exe)?\x22?\s+(avira|cb|cylance|defender|kaspersky|kes|mc|sec|sentinel|symantec|virus|wrsa|opssvc|avastui|avgui|bdservicehost|nsWscSvc|ekrn|sophoshealth|falcon)\x22?$")

Stage 3: table

| table _time, host, user, process, process_*, parent_*

Stage 4: bucket

| bin span=1s

Stage 5: stats

| stats values(*) as * by _time, host

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
EventCodeeq
  • 1 corpus 241 (splunk 225, kusto 15, elastic 1)
field:"EventID" kind:eq value:"1"
processregex_match
  • "(?i)\w+(.exe)?\x22?\s+(avira|cb|cylance|defender|kaspersky|kes|mc|sec|sentinel|symantec|virus|wrsa|opssvc|avastui|avgui|bdservicehost|nsWscSvc|ekrn|sophoshealth|falcon)\x22?$" corpus 3 (splunk 3)
field:"CommandLine" kind:regex_match
process_pathregex_match
    • "(?i)\x5cWindows\x5cSystem32\x5cfindstr.exe
    • \x5cWindows\x5cSysWOW64\x5cfind.exe"
    corpus 2 (splunk 2)
field:"process_name" kind:regex_match

Search terms

These SPL tokens match against raw event text.

StageTerm
1"<EventID>1<"
1"findstr.exe"
1findstr
1"find.exe"
1find
1"avira"
1"cb"
1"cylance"
1"defender"
1"kaspersky"
1"kes"
1"mc"
1"sec"
1"sentinel"
1"symantec"
1"virus"
1"wrsa"
1"opssvc"
1"avastui"
1"avgui"
1"bdservicehost"
1"nsWscSvc"
1"ekrn"
1"sophoshealth"
1"falcon"