Doser
Table of Contents
Overview
Executive Summary
Doser is a classification assigned to a specific category of malicious utilities (HackTools) and Trojans designed to execute Denial of Service (DoS) or Distributed Denial of Service (DDoS) attacks. Unlike stealthy malware designed for espionage or data theft, Doser's sole objective is brute-force disruption: overwhelming a target web server, network, or IP address with a massive flood of anomalous traffic, rendering the service unavailable to legitimate users.Infection Vector and Technical Capabilities
Doser tools are often standalone executables downloaded manually by "script kiddies" from hacking forums. However, in an enterprise context, a "Doser" detection often indicates that a corporate endpoint has been silently compromised and conscripted into a larger botnet, tasked with participating in coordinated DDoS attacks against external targets. Upon execution, Doser prioritizes rapid, high-volume network activity:- Traffic Generation: The malware is engineered to generate a massive volume of network packets. This can take various forms depending on the target, including UDP floods, TCP SYN floods (exhausting the server's connection state tables), or HTTP GET/POST floods (exhausting web server application resources).
- Command and Control (Botnet Clients): If the Doser is part of a botnet, it runs silently in the background, maintaining a persistent connection to a C2 server (often via IRC or HTTP). When the botmaster issues a command, the infected machine immediately begins attacking the specified target IP address.
- Resource Exhaustion: The sheer volume of packets generated by a Doser attack often exhausts the outbound bandwidth of the infected host's network, causing secondary disruptions for legitimate users on the same LAN.
Threat Assessment
The presence of Doser malware is a significant security incident. If an internal machine is participating in a DDoS attack, the organization's public IP address will likely be blacklisted by external ISPs and security vendors. Furthermore, the infection indicates a fundamental failure of endpoint security, as a threat actor was able to successfully execute arbitrary code.Incident Response and Remediation
- Immediate Network Isolation: The infected machine must be immediately isolated to halt the outbound flood of malicious traffic and prevent further participation in the DDoS attack.
- Network Traffic Analysis: Responders should analyze firewall and NetFlow logs to identify the specific C2 server the malware was communicating with, and block that infrastructure at the perimeter.
- Endpoint Eradication: Utilize enterprise EDR to terminate the Doser process and remove any associated persistence mechanisms (Run keys, Scheduled Tasks). Because botnet clients are often bundled with info-stealers, a thorough forensic sweep for secondary payloads is mandatory.
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 |
|---|---|---|---|
T1498.001 | Network Denial of Service: Direct Network Flood | Impact | ATT&CK ↗ |
T1498.002 | Network Denial of Service: Reflection Amplification (Used for Spam/DDoS) | Impact | ATT&CK ↗ |
T1059 | Command and Scripting Interpreter | Execution | ATT&CK ↗ |
Tactical Mitigations
Based on the techniques used by this family, consider the following defensive strategies:
- T1059: Restrict execution of scripting languages such as PowerShell, VBScript, or Python to authorized administrators. Enforce Script Block Logging.
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-SEA | Script Execution Analysis | Detect | T1059 | Analyze script block syntax and command arguments at runtime to detect malicious automation. |
D3-TR | Traffic Rate Limiting | Isolate | T1498.001 | Deploy BGP Flowspec and edge scrubbing proxies to automatically throttle volumetric SYN and UDP reflection attacks. |
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_DOSER_T1_ARTIFACT {
meta:
description = "Tier 1 Primitive Artifact: Raw string matches for Doser"
tier = "T1 - Primitive Artifact"
confidence = "Low-Medium (Fast Triage)"
author = "SystemHelpdesk Threat Research Desk"
date = "2026-10-14"
strings:
$s1 = "doser" ascii wide nocase
$s2 = "hacktool.doser" ascii wide nocase
$s3 = "trojan.ddos.doser" ascii wide nocase
$s4 = "win32/doser" 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 - Doser (Trojan) Execution & Triage
id: 8c262687-9ff1-5f59-b798-461b6b607d0e
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
with the Doser 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/doser
- 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.t1498_001
- attack.t1498_002
- attack.t1059
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: mediumTier 3 Attribution Fingerprint Rule (High Fidelity)
Deep signature matching distinctive operational fingerprints and payload characteristics.
rule MALWARE_WIN_DOSER_T3_ATTRIBUTION {
meta:
description = "Tier 3 Attribution Fingerprint: Heuristic detection for Doser 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 = "doser" 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.
- Sever network connectivity for the flagged endpoint to terminate persistent command-and-control (C2) communication channels and stop Doser from retrieving secondary stage payloads.
- Capture process memory triage to detect and terminate malicious threads injected by Doser into legitimate system processes such as explorer.exe or svchost.exe.
- Audit Windows Registry Run keys (HKCU\Software\Microsoft\Windows\CurrentVersion\Run) and Task Scheduler entries to locate and purge Doser persistence hooks.
- Deploy updated enterprise EDR detection signatures and conduct an out-of-band endpoint scan to isolate dropped binaries and staged payloads.
- Rotate all credentials, domain user passwords, and session cookies active on the system during the Doser execution timeframe.
What to Avoid
Common mistakes during response to this family that can destroy evidence, spread the infection, or worsen recovery.
- Do not assume the incident is resolved simply because an antivirus tool removed the initial Doser dropper; always verify that secondary payloads and persistence hooks have been eradicated.
- Avoid logging in with Domain Admin or privileged credentials on a machine suspected of running Doser until memory triage is complete.
- Do not delay host isolation; automated lateral movement and credential dumping can occur within minutes of initial execution.
References & External Analysis
- Search "doser" on VirusTotal (External Analysis)
- Search "doser" on Any.Run (Sandbox Sandbox)
- Search "doser" on MalwareBazaar (Malware Samples)
Frequently Asked Questions
What is Doser and what threat category does it belong to?
Doser is classified as a Trojan. Documented across security telemetry, it is engineered to execute unauthorized operations, establish persistent footholds on target endpoints, and facilitate malicious campaigns targeting enterprise and individual environments.
How does Doser establish persistence and evade defensive controls?
Doser typically establishes persistence through registry run keys, scheduled tasks, or service installations, while evading signature-based antivirus solutions through code obfuscation, memory injection, or anti-analysis sandbox checks.
What are the essential incident response steps for mitigating a Doser compromise?
Security teams responding to Doser should immediately isolate affected endpoints from the network, perform memory triage to capture volatile forensic artifacts, audit registry and startup persistence mechanisms, revoke exposed user credentials, and restore systems from verified, clean backups.
What secondary payloads and staging behaviors are commonly associated with HackTool.Doser?
HackTool.Doser frequently operates as a loader or dropper designed to establish a foothold before downloading and executing secondary high-impact malware payloads. Depending on the threat actor's objectives, these dropped modules can range from ransomware and banking injects to modular infostealers and remote management backdoors.
How can security operations teams effectively detect and hunt for HackTool.Doser across enterprise endpoints?
Defenders should hunt for HackTool.Doser by deploying behavioral endpoint detection and response (EDR) rules that monitor suspicious process spawning (such as cmd.exe or powershell.exe spawned from office documents or temporary directories), anomalous outbound network connections from non-browser binaries, and unauthorized modifications to Windows Run keys and scheduled task registries.
How do I remove Doser from Windows?
Manual removal of Doser 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 Doser infection?
Symptoms of Doser 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 Doser 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/doser.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.