Detection rules › Splunk

Rubeus Commands (Windows Event Log)

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

Rubeus is a C# toolset for raw Kerberos interaction and abuses

MITRE ATT&CK coverage

References

Telemetry coverage

Rule body

id: '5473.5639'
title: Rubeus Commands
description: 'Rubeus is a C# toolset for raw Kerberos interaction and abuses. -- Threat
  Actor Association: Wizard Spider - Software Association: Conti, Diavol, Quakbot/Qbot
  -- Atomics T1558.003 Test#2'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` TERM(exe) (TERM(EventCode=4688)
  OR "<EventID>4688<") (TERM(harvest) OR TERM(ptt) OR TERM(s4u) OR TERM(asktgt) OR
  TERM(brute) OR TERM(createnetonly) OR TERM(changepw) OR TERM(hash) OR TERM(tgssub)
  OR TERM(asktgs) OR TERM(renew) OR TERM(describe) OR TERM(monitor) OR TERM(purge)
  OR TERM(klist) OR TERM(triage) OR TERM(dump) OR TERM(tgtdeleg) OR TERM(kerberoast)
  OR TERM(asreproast) OR TERM(currentluid)) |regex process="(?i)\.exe\"?\s+(((harvest|ptt|s4u|asktgt|brute|createnetonly|changepw|hash|tgssub|asktgs|renew|describe|monitor)(\s+)?\/\w+\:)|((purge|klist|triage|dump|tgtdeleg|kerberoast|asreproast|currentluid)((\s+)?\/\w+)?))"
  | table _time, host, user, signature_id, process, process_id, process_name, parent_process_name
  | bin span=1s | stats values(*) as * by _time, host '
techniques:
- credential-access:steal or forge kerberos tickets
- credential-access:steal or forge kerberos tickets:golden ticket
- credential-access:steal or forge kerberos tickets:silver ticket
- credential-access:steal or forge kerberos tickets:kerberoasting
technique_id:
- T1558
- T1558.003
- T1558.002
- T1558.001
data_category:
- Windows event logs
references:
- https://github.com/GhostPack/Rubeus

Stages and Predicates

Stage 1: search

`get_endpoint_data` `get_endpoint_data_winevent` TERM(exe) (TERM(EventCode=4688) OR "<EventID>4688<") (TERM(harvest) OR TERM(ptt) OR TERM(s4u) OR TERM(asktgt) OR TERM(brute) OR TERM(createnetonly) OR TERM(changepw) OR TERM(hash) OR TERM(tgssub) OR TERM(asktgs) OR TERM(renew) OR TERM(describe) OR TERM(monitor) OR TERM(purge) OR TERM(klist) OR TERM(triage) OR TERM(dump) OR TERM(tgtdeleg) OR TERM(kerberoast) OR TERM(asreproast) OR TERM(currentluid))

Stage 2: regex

| regex process="(?i)\.exe\"?\s+(((harvest|ptt|s4u|asktgt|brute|createnetonly|changepw|hash|tgssub|asktgs|renew|describe|monitor)(\s+)?\/\w+\:)|((purge|klist|triage|dump|tgtdeleg|kerberoast|asreproast|currentluid)((\s+)?\/\w+)?))"

Stage 3: table

| table _time, host, user, signature_id, process, process_id, process_name, parent_process_name

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
  • 4688 corpus 317 (splunk 283, kusto 33, elastic 1)
field:"EventID" kind:eq value:"4688"
processregex_match
  • "(?i).exe\"?\s+(((harvest|ptt|s4u|asktgt|brute|createnetonly|changepw|hash|tgssub|asktgs|renew|describe|monitor)(\s+)?\/\w+\:)|((purge|klist|triage|dump|tgtdeleg|kerberoast|asreproast|currentluid)((\s+)?\/\w+)?))" corpus 3 (splunk 3)
field:"CommandLine" kind:regex_match

Search terms

These SPL tokens match against raw event text.

StageTerm
1exe
1"<EventID>4688<"
1harvest
1ptt
1s4u
1asktgt
1brute
1createnetonly
1changepw
1hash
1tgssub
1asktgs
1renew
1describe
1monitor
1purge
1klist
1triage
1dump
1tgtdeleg
1kerberoast
1asreproast
1currentluid