Pajetbin

Overview

Pajetbin (classified across threat telemetry as Ransom:Win32/Pajetbin, Trojan-Ransom.Win32.Pajetbin, and Win32/Pajetbin) is a destructive crypto-ransomware family targeting Windows workstations and network servers. Propagated through weaponized email phishing attachments, cracked software utilities, and exploit kits, Pajetbin performs swift host reconnaissance upon execution. It terminates active database processes, mail servers, and backup utilities via taskkill to release file system locks across local hard drives and mapped SMB network shares. Pajetbin encrypts target data files—including office documents, accounting spreadsheets, databases, and archives—using AES-256 encryption wrapped with an embedded RSA public key, appending a unique extension (such as .pajetbin) to locked files. It executes vssadmin delete shadows /all /quiet to purge Volume Shadow Copies and leaves ransom notices instructing victims on cryptocurrency extortion payments.

Known aliases

Threat reports may refer to this family under multiple names:

• Ransom:Win32/Pajetbin
• Trojan-Ransom.Win32.Pajetbin
• Win32/Pajetbin
• Ransom.Pajetbin
• Ransom:Win32/Pajetbin.A

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:

• T1566.001: Scan email attachments for malicious macros, scripts, or suspicious archive files.

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_PAJETBIN_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Pajetbin"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "pajetbin" ascii wide nocase
        $s2 = "ransom:win32/pajetbin" ascii wide nocase
        $s3 = "trojan-ransom.win32.pajetbin" ascii wide nocase
        $s4 = "win32/pajetbin" ascii wide nocase
        $s5 = "ransom.pajetbin" ascii wide nocase
        $s6 = "ransom:win32/pajetbin.a" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Pajetbin (Ransomware) Execution & Triage
id: 20992ab8-e1e1-5578-a0cb-e6460a9f9d22
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Pajetbin malware family. Detects volume shadow copy deletion, boot status
  tampering, and recovery inhibition characteristic of modern ransomware operations.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/pajetbin
- https://malware-families-catalog.systemhelpdesk.com/defensive/ransomware-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.ransomware
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1486
- attack.t1490
- attack.t1566_001
- attack.t1083
- attack.t1070_004
logsource:
  category: process_creation
  product: windows
detection:
  selection_process:
    Image|endswith:
    - \vssadmin.exe
    - \wmic.exe
    - \wbadmin.exe
    - \bcdedit.exe
    CommandLine|contains:
    - delete shadows
    - shadowcopy delete
    - resize shadowstorage
    - recoveryenabled no
    - ignoreallfailures
  condition: selection_process
falsepositives:
- Legitimate enterprise administrative scripts during approved change windows
- Authorized IT software deployment utilities and backup management agents
level: critical

rule MALWARE_WIN_PAJETBIN_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Pajetbin 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 = "pajetbin" 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 connections immediately to halt ransomware propagation across network shares.
2. Kill active ransomware processes using Task Manager or command-line commands.
3. Capture memory forensics and binary samples for malware analysis and IOC generation.
4. Block malicious email domains and delivery infrastructure across perimeter firewalls.
5. Rebuild affected systems and restore files from validated offline backup media.

What to Avoid

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

1. Do not pay the cryptocurrency ransom demand, as it encourages further cyberattacks without recovery guarantee.
2. Do not connect backup media to the affected machine before verifying full disinfection.

References & External Analysis

• Microsoft Defender Threat Encyclopedia - Ransom:Win32/Pajetbin
• Trend Micro Threat Encyclopedia - Ransom_Pajetbin
• Kaspersky Threat Intelligence Portal - Trojan-Ransom.Win32.Pajetbin
• Search "pajetbin" on VirusTotal (External Analysis)
• Search "pajetbin" on Any.Run (Sandbox Sandbox)
• Search "pajetbin" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Ransomware)

Explore other documented threats in the same operational category:

• Mirkov
• Wirzemro
• Loyeetro
• Mediaget
• Crytex
• Ssebot
• Imaut
• Baserch

Machine-readable

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