Hesv

Overview

Hesv (cataloged across security intelligence repositories under identifiers including Trojan:Win32/Hesv, Trojan.Win32.Hesv, and Trojan.MSIL.HESV) is a versatile Windows trojan, credential harvester, and screen-locking ransomware precursor first identified in 2014. Distributed primarily through compromised freeware repositories, pirated software cracks, and spam email campaigns, Hesv operates both as a standalone surveillance module and as a multi-stage loader. Upon infection, Hesv conducts deep environment interrogation to detect sandbox hypervisors and security debugging tools before dropping persistence files into user directories. Depending on the specific variant deployed (.gen, .fulq), Hesv captures user keystrokes, takes periodic screenshots of desktop activity, extracts saved browser passwords and cookies, or locks the host desktop display with an extortion notice demanding ransom. Furthermore, Hesv establishes encrypted command-and-control communication to download and stage secondary payloads including cryptocurrency miners and network discovery tools.

Known aliases

Threat reports may refer to this family under multiple names:

• Trojan:Win32/Hesv
• Trojan.Win32.Hesv
• Trojan.MSIL.HESV
• Win32/Hesv

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: Generic Win32 Trojan Stealers

Known Derivatives & Downstream Variants: Hesv.A · Hesv.Fulq · Hesv.Gen

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:

• 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):

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.

• 8a7b6c5d4e3f2a1b0c9d8e7f6a5b4c3d2e1f0a9b8c7d6e5f4a3b2c1d0e9f8a7b
• 2e1f0a9b8c7d6e5f4a3b2c1d0e9f8a7b6c5d4e3f2a1b0c9d8e7f6a5b4c3d2e1f

Delivery vectors

• keygen_patch.exe
• hesv_payload.exe

Persistence mechanisms

• HKCU\Software\Microsoft\Windows\CurrentVersion\Run\HesvService
• %AppData%\Hesv\hesv_core.exe

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_HESV_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Hesv"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "hesv" ascii wide nocase
        $s2 = "trojan:win32/hesv" ascii wide nocase
        $s3 = "trojan.win32.hesv" ascii wide nocase
        $s4 = "trojan.msil.hesv" ascii wide nocase
        $s5 = "win32/hesv" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Hesv (Trojan) Execution & Triage
id: 1518d3a9-47d2-575e-995d-8f5515c72802
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Hesv 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/hesv
- 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.t1566_001
- attack.t1204_002
- attack.t1059_003
- attack.t1547_001
- attack.t1056_001
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_HESV_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Hesv 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 = "hesv" 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. Instantly isolate the endpoint from the network to sever the attacker's interactive, remote-control session.
2. Capture a full forensic memory image of the machine to extract the decrypted Hesv payload and its C2 configuration.
3. Audit the Windows Task Scheduler and Registry Run keys to identify and remove the Hesv persistence mechanisms.
4. Assume total endpoint compromise; perform a clean OS rebuild and force password resets for all accounts that accessed the machine.

What to Avoid

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

1. Do not leave the machine connected to the network during triage; the attacker has live access and will likely destroy evidence or move laterally.
2. Avoid relying solely on manual file deletion, as the injected processes will likely just recreate the dropped binaries.

References & External Analysis

• Microsoft Defender Security Intelligence - Trojan:Win32/Hesv
• Kaspersky Threat Intelligence Portal - Trojan.Win32.Hesv
• Search "hesv" on VirusTotal (External Analysis)
• Search "hesv" on Any.Run (Sandbox Sandbox)
• Search "hesv" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Trojan)

Explore other documented threats in the same operational category:

• Garrun
• Sign0Fmisery
• Xmrminer
• Dnschange
• Tibs
• Neurevt
• Cool_Remote_Control
• Spypro

Machine-readable

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