Credential Dumping Attempt Via WerFault

Severity: high
Author: Florian Roth (Nextron Systems)
Source: upstream

Detects process LSASS memory dump using Mimikatz, NanoDump, Invoke-Mimikatz, Procdump or Taskmgr based on the CallTrace pointing to ntdll.dll, dbghelp.dll or dbgcore.dll for win10, server2016 and up.

MITRE ATT&CK coverage

Tactic	Techniques
Credential Access	`T1003.001` OS Credential Dumping: LSASS Memory

Event coverage

Provider	Event ID	Title
Sysmon	10	ProcessAccess

Stages and Predicates

Stage 1: `selection`

GrantedAccess: 0x1FFFFF
SourceImage|endswith: '\WerFault.exe'
TargetImage|endswith: '\lsass.exe'

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.

Field	Kind	Values
`GrantedAccess`	eq	`0x1FFFFF` corpus 3 (sigma 3)
`SourceImage`	ends_with	`\WerFault.exe` corpus 8 (sigma 8)
`TargetImage`	ends_with	`\lsass.exe` corpus 13 (sigma 13)

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.

Potentially Suspicious GrantedAccess Flags On LSASS [sigma] (drops 2 filters this rule applies) (first-stage match only; downstream stages may differ)