Terminal Server Client Connection History Cleared - Registry

Severity: high
Author: Christian Burkard (Nextron Systems)
Source: upstream

Detects the deletion of registry keys containing the MSTSC connection history

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1112` Modify Registry
Defense Evasion	`T1070` Indicator Removal, `T1112` Modify Registry

Event coverage

Provider	Event ID	Title
Sysmon	14	RegistryEvent (Key and Value Rename)

Stages and Predicates

Stage 1: `1 of selection1`

EventType: DeleteValue
TargetObject|contains: '\Microsoft\Terminal Server Client\Default\MRU'

Stage 2: `1 of selection2`

EventType: DeleteKey
TargetObject|contains: '\Microsoft\Terminal Server Client\Servers\'

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
`EventType`	eq	`DeleteKey` `DeleteValue` corpus 5 (sigma 4, splunk 1)
`TargetObject`	match	`\Microsoft\Terminal Server Client\Default\MRU` `\Microsoft\Terminal Server Client\Servers\`