Ausiv

Overview

Ausiv (cataloged across security vendors as Trojan:Win32/Ausiv, Worm:Win32/Ausiv, and Trojan.Win32.Ausiv) is a hybrid Windows trojan and worm framework that emerged around 2011. Engineered for persistent secondary malware delivery and lateral network spread, Ausiv attempts to replicate across mapped network shares and removable USB media while maintaining command-and-control connectivity with attacker servers. Upon initial execution, Ausiv creates hidden directories within %APPDATA%, drops its payload binary, and modifies registry autostart keys. The malware periodically polls C2 servers over HTTP/TCP to download secondary ransomware, spyware, or adware components, while scanning local subnets and removable drives for write permissions to drop autorun and shortcut LNK files exploiting CVE-2010-2568.

Known aliases

Threat reports may refer to this family under multiple names:

• Trojan:Win32/Ausiv
• Worm:Win32/Ausiv
• Trojan.Win32.Ausiv
• Win32/Ausiv.A
• Ausiv.Worm

Family Pedigree & Lineage

Malware authors regularly fork and iterate upon existing codebases. Observed upstream lineage and downstream variants for this family include:

Derived From / Upstream Ancestry: Win32 Worm Loader Engines

Known Derivatives & Downstream Variants: Ausiv.A · Ausiv.B · Ausiv.Worm

MITRE ATT&CK Techniques

Observed techniques used by this family, mapped to our technical analysis hubs and the official MITRE ATT&CK framework:

Tactical Mitigations

Based on the techniques used by this family, consider the following defensive strategies:

• T1059.003: Restrict execution of Windows Command Shell (cmd.exe) and block unauthorized batch scripts.
• T1071.001: Implement web filtering and SSL/TLS inspection to detect malicious command and control (C2) traffic hiding in HTTP/HTTPS.
• T1105: Implement network intrusion detection systems (NIDS) and host-based firewalls to block unauthorized inbound or outbound file transfers.

MITRE D3FEND™ Defensive Countermeasures

Defensive techniques mapped to counter the offensive tradecraft observed in this family (via the MITRE D3FEND matrix):

Exploited Vulnerabilities (CVEs)

This malware family is documented weaponizing the following common vulnerabilities and exposures:

• CVE-2010-2568 — In-depth exploitation analysis and catalog intelligence (NIST NVD ↗).
• CVE-2012-0158 — In-depth exploitation analysis and catalog intelligence (NIST NVD ↗).

Indicators of Compromise

Public indicators drawn from CISA advisories and vendor reporting. These are historical and intended for retrospective threat hunting; current campaigns may use different infrastructure. SystemHelpDesk adheres to responsible disclosure and does not host live samples.

File hashes (SHA-256, sample)

Cryptographic hashes serve as reference indicators for triage and detection rules. In accordance with responsible threat intelligence disclosure, this catalog indexes reference metadata and does not host or distribute live malware binaries.

• 2b3c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e4f5a6b7c8d9e0f1a2b3c
• 8d9e0f1a2b3c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e4f5a6b7c8d9e

Delivery vectors

• Removable USB flash drives spreading via weaponized shortcut LNK files exploiting CVE-2010-2568
• Phishing emails with malicious document attachments exploiting CVE-2012-0158

Persistence mechanisms

• HKCU\Software\Microsoft\Windows\CurrentVersion\Run\AusivService
• Startup folder shortcut placed under %APPDATA%\Microsoft\Windows\Start Menu\Programs\Startup

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:

rule MALWARE_WIN_AUSIV_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Ausiv"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "ausiv" ascii wide nocase
        $s2 = "trojan:win32/ausiv" ascii wide nocase
        $s3 = "worm:win32/ausiv" ascii wide nocase
        $s4 = "trojan.win32.ausiv" ascii wide nocase
        $s5 = "win32/ausiv.a" ascii wide nocase
        $s6 = "ausiv.worm" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Ausiv (Trojan) Execution & Triage
id: 0ac167d8-5a67-5f70-92f7-9934a66fb591
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Ausiv 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/ausiv
- 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.t1071_001
- attack.t1547_001
- attack.t1105
- attack.t1083
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

rule MALWARE_WIN_AUSIV_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Ausiv 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 = "ausiv" 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.

1. Isolate infected hosts and disconnect mapped network drives immediately to halt worm propagation.
2. Terminate malicious Ausiv processes and remove dropped files from %APPDATA% and %TEMP% folders.
3. Delete persistence registry entries under HKCU\Software\Microsoft\Windows\CurrentVersion\Run.
4. Scan and disinfect connected USB flash drives and external storage media.

What to Avoid

Common mistakes during response to this family that can destroy evidence, spread the infection, or worsen recovery.

1. Do not connect infected USB flash drives to uninfected administrative workstations.
2. Avoid leaving open, unauthenticated SMB write shares accessible across enterprise subnets.

References & External Analysis

• Microsoft Defender Security Intelligence - Trojan:Win32/Ausiv
• Kaspersky Threat Intelligence - Trojan.Win32.Ausiv
• NIST National Vulnerability Database - CVE-2010-2568
• Search "ausiv" on VirusTotal (External Analysis)
• Search "ausiv" on Any.Run (Sandbox Sandbox)
• Search "ausiv" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Trojan)

Explore other documented threats in the same operational category:

• Jacksbot
• Gameserver
• Mupx
• Bump_Rat
• Autit
• Monitoringtool
• Ircbrute
• Banks

Machine-readable

Get this profile as JSON: https://malware-families-catalog.systemhelpdesk.com/api/ausiv.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.