Windows Suspicious UltraVNC Command Line With Auto-Reconnect Flags
Alerts on UltraVNC execution using -autoreconnect with -connect and -id in the Windows command line.
- Product
- windows
- Category
- process_creation
- Author
- Bhabesh Raj (SigmaHQ), DRL 1.1
- Published
- 2022-03-04
- Updated
- 2026-07-30
ATT&CK techniques
Lateral MovementRecon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule flags process creation events where the command line contains the UltraVNC auto-reconnect flag, along with a connection string and an ID parameter. Attackers can use these options to automatically re-establish a remote connection after execution, increasing persistence and reducing operator involvement. Detection relies on Windows process creation telemetry and string matches within the full command line.
Reporting behind it
- web.archive.orghttps://web.archive.org/web/20220224045756/https://www.ria.ee/sites/default/files/content-editors/kuberturve/tale_of_gamaredon_infection.pdf
- symantec-enterprise-blogs.security.comhttps://symantec-enterprise-blogs.security.com/blogs/threat-intelligence/shuckworm-gamaredon-espionage-ukraine
- unit42.paloaltonetworks.comhttps://unit42.paloaltonetworks.com/unit-42-title-gamaredon-group-toolset-evolution
- uvnc.comhttps://uvnc.com/docs/uvnc-viewer/52-ultravnc-viewer-commandline-parameters.html
- github.comhttps://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_ultravnc_susp_execution.yml
Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.
title: Windows Suspicious UltraVNC Command Line With Auto-Reconnect Flags
id: 5e488782-f1ed-4e67-8a67-2076a6fcafc6
status: test
description: This rule flags process creation events where the command line contains the UltraVNC auto-reconnect flag, along with a connection string and an ID parameter. Attackers can use these options to automatically re-establish a remote connection after execution, increasing persistence and reducing operator involvement. Detection relies on Windows process creation telemetry and string matches within the full command line.
references:
- https://web.archive.org/web/20220224045756/https://www.ria.ee/sites/default/files/content-editors/kuberturve/tale_of_gamaredon_infection.pdf
- https://symantec-enterprise-blogs.security.com/blogs/threat-intelligence/shuckworm-gamaredon-espionage-ukraine
- https://unit42.paloaltonetworks.com/unit-42-title-gamaredon-group-toolset-evolution
- https://uvnc.com/docs/uvnc-viewer/52-ultravnc-viewer-commandline-parameters.html
- https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_ultravnc_susp_execution.yml
author: Bhabesh Raj, Huntrule Team
date: 2022-03-04
modified: 2022-03-09
tags:
- attack.lateral-movement
- attack.g0047
- attack.t1021.005
logsource:
category: process_creation
product: windows
detection:
selection:
CommandLine|contains|all:
- "-autoreconnect "
- "-connect "
- "-id:"
condition: selection
falsepositives:
- Unknown
level: high
license: DRL-1.1
related:
- id: 871b9555-69ca-4993-99d3-35a59f9f3599
type: derived