Created Files by Microsoft Sync Center

Severity: medium
Author: elhoim
Source: upstream

This rule detects suspicious files created by Microsoft Sync Center (mobsync)

MITRE ATT&CK coverage

Tactic	Techniques
Privilege Escalation	`T1055` Process Injection
Defense Evasion	`T1055` Process Injection, `T1218` System Binary Proxy Execution

Event coverage

Provider	Event ID	Title
Sysmon	11	FileCreate

Stages and Predicates

Stage 1: `selection_mobsync`

Image|endswith: '\mobsync.exe'

Stage 2: `filter_created_file`

or:
TargetFilename|endswith: .dll
TargetFilename|endswith: .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
`Image`	ends_with	`\mobsync.exe` corpus 2 (sigma 2)
`TargetFilename`	ends_with	`.dll` corpus 21 (sigma 21) `.exe` corpus 18 (sigma 18)