Detection rules › Sigma
Potentially Suspicious Execution Of Regasm/Regsvcs From Uncommon Location
Detects potentially suspicious execution of the Regasm/Regsvcs utilities from a potentially suspicious location
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Stealth | T1218.009 System Binary Proxy Execution: Regsvcs/Regasm |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
Rule body yaml
title: Potentially Suspicious Execution Of Regasm/Regsvcs From Uncommon Location
id: cc368ed0-2411-45dc-a222-510ace303cb2
related:
- id: e9f8f8cc-07cc-4e81-b724-f387db9175e4
type: derived
status: test
description: Detects potentially suspicious execution of the Regasm/Regsvcs utilities from a potentially suspicious location
references:
- https://www.fortiguard.com/threat-signal-report/4718?s=09
- https://lolbas-project.github.io/lolbas/Binaries/Regasm/
- https://lolbas-project.github.io/lolbas/Binaries/Regsvcs/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-08-25
modified: 2023-02-13
tags:
- attack.stealth
- attack.t1218.009
logsource:
category: process_creation
product: windows
detection:
selection_img:
- Image|endswith:
- '\Regsvcs.exe'
- '\Regasm.exe'
- OriginalFileName:
- 'RegSvcs.exe'
- 'RegAsm.exe'
selection_dir:
CommandLine|contains:
# Note: Add more potentially suspicious directories
- '\AppData\Local\Temp\'
- '\Microsoft\Windows\Start Menu\Programs\Startup\'
- '\PerfLogs\'
- '\Users\Public\'
- '\Windows\Temp\'
# - '\Desktop\'
# - '\Downloads\'
condition: all of selection_*
falsepositives:
- Unknown
level: medium
Stages and Predicates
Stage 0: condition
all of selection_*Stage 1: selection_img
selection_img:
- Image|endswith:
- '\Regsvcs.exe'
- '\Regasm.exe'
- OriginalFileName:
- 'RegSvcs.exe'
- 'RegAsm.exe'
Stage 2: selection_dir
selection_dir:
CommandLine|contains:
- '\AppData\Local\Temp\'
- '\Microsoft\Windows\Start Menu\Programs\Startup\'
- '\PerfLogs\'
- '\Users\Public\'
- '\Windows\Temp\'
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 |
|---|---|---|
CommandLine | match |
|
Image | ends_with |
|
OriginalFileName | eq |
|