Detection rules › Splunk

ZeroLogon CVE-2020-1472 (Windows Event Log)

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

The vulnerability allows an attacker to set a password for the computer account of an Active Directory Domain Controller, which can then be abused to pull credentials from the Domain Controller

MITRE ATT&CK coverage

References

Event coverage

Rule body yaml

id: '5366.5480'
title: ZeroLogon CVE-2020-1472
description: 'The vulnerability allows an attacker to set a password for the computer
  account of an Active Directory Domain Controller, which can then be abused to pull
  credentials from the Domain Controller. -- Threat Actor Association: APT15, APT29/Nobelium/Cozy
  Bear - Software Association: BianLian, BlackSuit, Bumblebee Loader, Cuba, LockBit,
  Qbot/Qakbot - #TrendingThreat #Russia #Ukraine'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` ((TERM(EventCode=4742) OR
  "<EventID>4742<") "NT AUTHORITY" "ANONYMOUS LOGON")| regex host="(?i)dc" | rex field=_raw
  "(?i)Changed:\s+Security ID:\s+(?<dest_host>[\S]+)" | table _time, host, user signature_id,
  member_nt_domain, user, dest_host | bin span=1s | stats values(*) as * by _time,
  host '
techniques:
- privilege-escalation:exploitation for privilege escalation
- lateral-movement:exploitation of remote services
technique_id: 
- T1068
- T1210
data_category:
- Windows event logs
references:
- https://www.secura.com/pathtoimg.php?id=2055
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2020-1472

Stages and Predicates

Stage 1: search

`get_endpoint_data` `get_endpoint_data_winevent` ((TERM(EventCode=4742) OR "<EventID>4742<") "NT AUTHORITY" "ANONYMOUS LOGON")

Stage 2: regex

| regex host="(?i)dc"

Stage 3: rex

| rex field=_raw "(?i)Changed:\s+Security ID:\s+(?<dest_host>[\S]+)"

Stage 4: table

| table _time, host, user signature_id, member_nt_domain, user, dest_host

Stage 5: bucket

| bin span=1s

Stage 6: stats

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

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
EventCodeeq
  • 4742 corpus 6 (splunk 6)
hostregex_match
  • "(?i)dc"

Search terms

Bare-string tokens in the SPL search body. Splunk matches each token against _raw (the untyped raw event text) anywhere it appears, not against a specific field. These don't surface in the Indicators table because they aren't predicates on a known field.

StageTerm
1TERM
1"<EventID>4742<"
1"NT AUTHORITY"
1"ANONYMOUS LOGON"