Infinitetear

Overview

Executive Summary

Infection Vector and Technical Capabilities

• Deep Stealth and Evasion: The malware often operates entirely in memory (fileless execution) to evade disk-based anti-virus scans. It employs complex API hooking and process hollowing to inject itself into legitimate system processes (like `svchost.exe`), masking its execution.
• Custom Encrypted C2: InfiniteTear utilizes highly customized, encrypted protocols for Command and Control (C2) communication. It often blends its traffic with legitimate protocols (like HTTPS or DNS) and utilizes domain generation algorithms (DGAs) or hardcoded, compromised infrastructure to make detection difficult.
• Advanced Espionage Toolset: The backdoor provides a comprehensive suite of espionage tools, allowing operators to execute arbitrary commands, harvest credentials from LSASS memory, capture screens, log keystrokes, and silently compress and exfiltrate specific files or databases.

Threat Assessment

Incident Response and Remediation

• Forensic Triage and Containment: Do not immediately wipe the machine. Isolate the endpoint from the internet, but keep it powered on to allow Incident Response teams to capture volatile memory (RAM) to analyze the memory-resident components and identify the C2 infrastructure.
• Enterprise-Wide Threat Hunt: The presence of InfiniteTear on one endpoint guarantees lateral movement has occurred. A comprehensive enterprise-wide threat hunt must be initiated to identify all compromised assets, stolen credentials, and secondary backdoors.
• Complete Architecture Review: Remediation requires a full rebuild of the compromised endpoints from clean baselines, a complete reset of the Active Directory environment (including the KRBTGT account), and a fundamental review of network segmentation and access controls.

Known aliases

Threat reports may refer to this family under multiple names:

• Backdoor.InfiniteTear
• APT.InfiniteTear
• Trojan.Tear

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:

• T1003.001: Monitor for LSASS memory dumping or registry SAM extraction. Enable Credential Guard on Windows systems.
• 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.

MITRE D3FEND™ Defensive Countermeasures

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

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_INFINITETEAR_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Infinitetear"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "infinitetear" ascii wide nocase
        $s2 = "backdoor.infinitetear" ascii wide nocase
        $s3 = "apt.infinitetear" ascii wide nocase
        $s4 = "trojan.tear" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Infinitetear (Trojan) Execution & Triage
id: 666e63eb-6d32-5cd7-9610-80ceea98cf66
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Infinitetear 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/infinitetear
- 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.t1055
- attack.t1071_001
- attack.t1003_001
- attack.t1048
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_INFINITETEAR_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Infinitetear 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 = "infinitetear" 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. Sever network connectivity for the flagged endpoint to terminate persistent command-and-control (C2) communication channels and stop Infinitetear from retrieving secondary stage payloads.
2. Capture process memory triage to detect and terminate malicious threads injected by Infinitetear into legitimate system processes such as explorer.exe or svchost.exe.
3. Audit Windows Registry Run keys (HKCU\Software\Microsoft\Windows\CurrentVersion\Run) and Task Scheduler entries to locate and purge Infinitetear persistence hooks.
4. Deploy updated enterprise EDR detection signatures and conduct an out-of-band endpoint scan to isolate dropped binaries and staged payloads.
5. Rotate all credentials, domain user passwords, and session cookies active on the system during the Infinitetear execution timeframe.

What to Avoid

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

1. Do not assume the incident is resolved simply because an antivirus tool removed the initial Infinitetear dropper; always verify that secondary payloads and persistence hooks have been eradicated.
2. Avoid logging in with Domain Admin or privileged credentials on a machine suspected of running Infinitetear until memory triage is complete.
3. Do not delay host isolation; automated lateral movement and credential dumping can occur within minutes of initial execution.

References & External Analysis

• Search "infinitetear" on VirusTotal (External Analysis)
• Search "infinitetear" on Any.Run (Sandbox Sandbox)
• Search "infinitetear" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Trojan)

Explore other documented threats in the same operational category:

• Pcfixer
• Ymkfawdgfnmi
• Backswap
• Gameserver
• Banks
• Potao
• Smshoax
• Montague

Machine-readable

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