Hide Schedule Task Via Index Value Tamper

Severity: high
Author: Nasreddine Bencherchali (Nextron Systems)
Source: upstream

Detects when the "index" value of a scheduled task is modified from the registry Which effectively hides it from any tooling such as "schtasks /query" (Read the referenced link for more information about the effects of this technique)

MITRE ATT&CK coverage

Tactic	Techniques
Defense Evasion	`T1562` Impair Defenses

Event coverage

Provider	Event ID	Title
Sysmon	13	RegistryEvent (Value Set)

Stages and Predicates

Stage 1: `selection`

Details: 'DWORD (0x00000000)'
TargetObject|contains: Index
TargetObject|contains: '\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache\Tree\'

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.