Detection rules › Splunk

Windows Steal Authentication Certificates CryptoAPI

Author
Michael Haag, Splunk
Source
upstream

The following analytic detects the extraction of authentication certificates using Windows Event Log - CAPI2 (CryptoAPI 2). It leverages EventID 70, which is generated when a certificate's private key is acquired. This detection is significant because it can identify potential misuse of certificates, such as those extracted by tools like Mimikatz or Cobalt Strike. If confirmed malicious, this activity could allow attackers to impersonate users, escalate privileges, or access sensitive information, posing a severe risk to the organization's security.

MITRE ATT&CK coverage

TacticTechniques
Credential AccessT1649 Steal or Forge Authentication Certificates

Event coverage

ProviderEvent IDTitle
CAPI270For more details for this event, please refer to the "Details" section

Stages and Predicates

Stage 1: search

search EventCode=70

Stage 2: xmlkv

xmlkv

Stage 3: stats

stats BY Computer, UserData_Xml

Stage 4: rename

rename

Stage 5: search

search

Stage 6: search

search

Stage 7: search

search `macro`

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
  • 70

Neighbors

Broader alternatives (more inclusive than this rule)

These rules match a superset of what this rule catches. They cover the same events plus more. Use them if you want wider coverage and can absorb more false positives.