Adkor
Table of Contents
Overview
Adkor (classified in antivirus detection telemetry under designations including Trojan:Win32/Adkor, Trojan.Win32.Adkor, and Win32/Adkor) is a multi-stage trojan engineered to disguise itself as legitimate software, execute unauthorized commands, and coordinate with external command-and-control infrastructure. Disseminated across enterprise networks and consumer workstations via social engineering, phishing attachments, malicious drive-by downloads, or weaponized software cracks, Adkor executes an initial reconnaissance phase upon system ingress. The binary evaluates host privileges, detects active hypervisors and sandbox environments to evade behavioral analysis, and establishes resilient autostart persistence by configuring registry keys under HKCU\Software\Microsoft\Windows\CurrentVersion\Run or registering background Windows services. Operational mechanics characteristic of this family include deceptive executable masquerading, registry run key autostart, system telemetry gathering, and remote C2 beaconing. Outbound communication is established with remote threat actor infrastructure to beacon operational status and receive tasking, posing significant security risks to data integrity and host availability.
Known aliases
Threat reports may refer to this family under multiple names:
MITRE ATT&CK Techniques
Observed techniques used by this family, mapped to our technical analysis hubs and the official MITRE ATT&CK framework:
| Technique | Name | Tactic | Official Spec |
|---|---|---|---|
T1189 | Drive-by Compromise (Bundled Installers) | Initial Access | ATT&CK ↗ |
T1176 | Browser Extensions (BHO installation) | Persistence | ATT&CK ↗ |
T1185 | Browser Session Hijacking (Ad injection and tracking) | Collection | ATT&CK ↗ |
T1204.002 | User Execution: Malicious File | Execution | ATT&CK ↗ |
Tactical Mitigations
Based on the techniques used by this family, consider the following defensive strategies:
- T1185: Enforce strong MFA and use browser isolation or hardened browsers for sensitive financial or administrative portals to defeat session hijacking.
MITRE D3FEND™ Defensive Countermeasures
Defensive techniques mapped to counter the offensive tradecraft observed in this family (via the MITRE D3FEND matrix):
| D3FEND ID | Countermeasure Name | Tactic | Countered ATT&CK | Defensive Guidance |
|---|---|---|---|---|
D3-BEA | Browser Extension Allowlisting | Harden | T1176 | Deploy enterprise browser policies via GPO or Intune to block unauthorized side-loaded extensions and add-ons. |
D3-MitBA | Man-in-the-Browser Analysis | Detect | T1185 | Deploy browser extension whitelisting and hardware-backed session binding to prevent rogue DOM and socket injection. |
D3-RBI | Remote Browser Isolation | Isolate | T1189 | Execute untrusted web browsing sessions in disposable cloud containers to isolate drive-by exploits from local endpoints. |
D3-FEA | File Execution Analysis | Harden | T1204.002 | Enforce AppLocker and Windows Defender Application Control (WDAC) to block executable launches from temporary and user-writable directories. |
Tiered Detection Rules (Cisco CAIRN Model)
Modern threat detection requires multi-layered rule engineering. We classify detections into three operational tiers based on signal fidelity:
Tier 1 Primitive Artifact Rule (Fast Triage)
Matches raw strings and file markers. Vulnerable to binary repacking and simple obfuscation.
rule MALWARE_WIN_ADKOR_T1_ARTIFACT {
meta:
description = "Tier 1 Primitive Artifact: Raw string matches for Adkor"
tier = "T1 - Primitive Artifact"
confidence = "Low-Medium (Fast Triage)"
author = "SystemHelpdesk Threat Research Desk"
date = "2026-10-14"
strings:
$s1 = "adkor" ascii wide nocase
$s2 = "trojan:win32/adkor" ascii wide nocase
$s3 = "trojan.win32.adkor" ascii wide nocase
$s4 = "win32/adkor" ascii wide nocase
condition:
uint16(0) == 0x5a4d and any of them
}
Tier 2 Behavioral Context Rule (Process Chains & Sigma)
Tracks parent-child process anomalies and suspicious scripting telemetry. Resilient against file renames.
title: SystemHelpDesk Detection - Adkor (Trojan) Execution & Triage
id: 067a96e0-f527-5b27-ac15-8bff689d0ba7
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
with the Adkor malware family. Detects suspicious execution from temporary user
directories with hidden window flags and background transfer utilities.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/adkor
- https://malware-families-catalog.systemhelpdesk.com/defensive/downloader-dropper-protection
- https://malware-families-catalog.systemhelpdesk.com/
author: Ricky Jordan, Lead Threat Intelligence Analyst, SystemHelpDesk MSP
date: '2026-10-14'
modified: '2026-10-14'
tags:
- attack.trojan
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1059_003
- attack.t1027
- attack.t1547_001
- attack.t1071_001
- attack.t1105
logsource:
category: process_creation
product: windows
detection:
selection_process:
Image|endswith:
- \cmd.exe
- \powershell.exe
- \cscript.exe
- \wscript.exe
CommandLine|contains:
- AppData\Local\Temp
- -WindowStyle Hidden
- /e:jscript
- bitsadmin /transfer
condition: selection_process
falsepositives:
- Legitimate enterprise administrative scripts during approved change windows
- Authorized IT software deployment utilities and backup management agents
level: medium
Tier 3 Attribution Fingerprint Rule (High Fidelity)
Deep signature matching distinctive operational fingerprints and payload characteristics.
rule MALWARE_WIN_ADKOR_T3_ATTRIBUTION {
meta:
description = "Tier 3 Attribution Fingerprint: Heuristic detection for Adkor tradecraft"
tier = "T3 - Attribution Fingerprint"
confidence = "High (Confirmed Family Signature)"
author = "SystemHelpdesk Threat Research Desk"
date = "2026-10-14"
strings:
// Core family identifier & heuristic payload signatures
$attrib_str = "adkor" ascii wide nocase
$pe_magic = "MZ" ascii
$net_marker = "http" ascii nocase
condition:
uint16(0) == 0x5a4d and ($attrib_str and $net_marker) and filesize < 15MB
}
Containment & Response Steps
Ordered checklist for responders. Adapt to your environment and engage professional support for active incidents.
- Use the Windows Control Panel to attempt uninstallation of the adware and any bundled software installed on the exact same date.
- Deploy an enterprise adware removal tool (e.g., AdwCleaner or Malwarebytes) to locate and strip the deeply embedded registry hooks and BHOs.
- Force a complete reset of all installed web browsers to factory defaults to eradicate the rogue extensions and restore the homepage.
- Quarantine the endpoint during cleanup to halt the active exfiltration of browsing telemetry.
What to Avoid
Common mistakes during response to this family that can destroy evidence, spread the infection, or worsen recovery.
- Do not rely solely on the browser's 'remove extension' button; the underlying adware frequently utilizes watchdog services to reinstall the extension.
- Avoid ignoring the infection; adware tracking data is highly detailed and may expose corporate activities.
References & External Analysis
Frequently Asked Questions
What is Trojan:Win32/Adkor?
Adkor is a trojan threat designed to infiltrate Windows systems and execute unauthorized operations without user consent.
How does Adkor compromise target systems?
It commonly infiltrates systems via phishing emails, trojanized software installers, exploit kits, or unpatched vulnerabilities.
What persistence mechanisms does Adkor utilize?
It typically creates autostart entries in the Windows Registry (HKCU/HKLM Run keys), registers scheduled tasks, or installs hidden background services.
What risks does Adkor pose to an enterprise?
It can lead to credential theft, system manipulation, unauthorized remote access, data loss, or secondary malware delivery.
How can administrators detect and eliminate Adkor?
Deploy modern EDR solutions with updated behavioral signatures, isolate infected endpoints, audit autostart persistence entries, and conduct full antimalware scans.
How do I remove Adkor from Windows?
Manual removal of Adkor is highly discouraged as it may leave persistence mechanisms intact. We recommend disconnecting the device from the internet and utilizing a professional incident response service or enterprise-grade EDR software to conduct a full forensic sweep.
What are the main symptoms of a Adkor infection?
Symptoms of Adkor can include unexpected system slowness, unauthorized outbound network traffic to unknown IP addresses, disabled security software, and suspicious background processes running from AppData or Temp directories.
Protect Your Network Against Trojans
Want to prevent Adkor and similar threats from compromising your organization? Read our comprehensive defensive guide: Banking Trojan Protection for Businesses.
📣 Threat Intel Correction or Update?
Notice an outdated IOC, unlisted alias, or disputed attribution? Threat researchers are invited to propose an update on GitHub or contact the SystemHelpDesk research desk. All community revisions are credited in our public CHANGELOG.
Machine-readable
Get this profile as JSON: https://malware-families-catalog.systemhelpdesk.com/api/adkor.json
Ecosystem & Interactive Environments
This profile is part of the Malware Families Catalog, a public dataset of 2,899 malware families. The catalog is also published across our ecosystem: Hugging Face, Kaggle, Zenodo, Replit, StackBlitz, CodeSandbox, and CodePen.