Sillyp2P

Overview

Executive Summary

Infection Vector and Technical Capabilities

• Shared Folder Replication: The worm immediately identifies the shared folders used by installed P2P client software. It copies its own executable into these folders hundreds or thousands of times.
• Deceptive Renaming (Baiting): The worm dynamically renames these copies based on a hardcoded list of popular search terms or by parsing the names of legitimate files already in the shared folder. A single worm might disguise itself as `Windows_10_Crack.exe`, `Latest_Movie_1080p.avi.exe`, and `Photoshop_Keygen.exe` simultaneously.
• Network Flooding: By placing thousands of highly desirable "bait" files into the P2P network, the infected machine becomes a major distribution node, significantly consuming the host's bandwidth and propagating the worm to other P2P users.

Threat Assessment

Remediation and Eradication

• P2P Client Termination: Immediately terminate any active P2P file-sharing software to halt the active distribution of the worm and stop bandwidth consumption.
• Full System Anti-Malware Scan: Run a comprehensive scan using a reputable enterprise antivirus solution to identify and remove all replicated copies of the worm executable across the filesystem.
• Network Policy Enforcement: P2P software is a massive security risk and should be strictly prohibited in enterprise environments. Enforce Application Control policies to block the execution of all P2P clients and utilize perimeter firewalls to block known P2P network ports and protocols.

Known aliases

Threat reports may refer to this family under multiple names:

• Worm.P2P.Silly
• P2P-Worm.Win32.Silly
• Win32/SillyP2P

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:

• T1036.005: Monitor for executable files running from unusual paths or with deceptive names. Use EDR to detect process masquerading.
• 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):

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_SILLYP2P_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Sillyp2P"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "sillyp2p" ascii wide nocase
        $s2 = "worm.p2p.silly" ascii wide nocase
        $s3 = "p2p-worm.win32.silly" ascii wide nocase
        $s4 = "win32/sillyp2p" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Sillyp2p (Ransomware) Execution & Triage
id: 10d08aa9-1285-570d-8240-8a1fa0d888ba
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Sillyp2p 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/sillyp2p
- 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.t1570
- attack.t1036_005
- attack.t1059
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_SILLYP2P_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Sillyp2P 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 = "sillyp2p" 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. Immediately isolate affected host(s) from the internal network (disconnect physical Ethernet and disable Wi-Fi/Bluetooth) to prevent Sillyp2P from spreading laterally or encrypting network-attached storage (NAS) and shared SMB volumes.
2. Preserve volatile system memory (RAM capture) on a representative endpoint before attempting a reboot or power-down, as Sillyp2P symmetric encryption keys or uncompiled payload components may still reside in memory.
3. Audit process execution logs and terminate active scripting interpreters (e.g. PowerShell, CMD, WScript) or commands executing 'vssadmin.exe delete shadows' or 'wbadmin' used by Sillyp2P to inhibit recovery.
4. Investigate the initial compromise vector (such as exposed RDP instances, spearphishing attachments, or vulnerable edge gateways) and enforce an immediate credential reset for all compromised Active Directory accounts.
5. Restore critical assets and databases exclusively from verified, air-gapped, or immutable offline backups once the Sillyp2P binary and related persistence hooks are eradicated.

What to Avoid

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

1. Do not restart or power cycle infected systems prematurely; doing so destroys volatile RAM encryption keys and may trigger bootloader locking logic embedded in Sillyp2P.
2. Avoid negotiating or paying the extortion demand without prior forensic evaluation and consultation with incident response specialists, as payment does not guarantee data recovery.
3. Do not connect clean backup drives or external storage to the affected network until Sillyp2P eradication is completely verified.

References & External Analysis

• Search "sillyp2p" on VirusTotal (External Analysis)
• Search "sillyp2p" on Any.Run (Sandbox Sandbox)
• Search "sillyp2p" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Ransomware)

Explore other documented threats in the same operational category:

• Adcrypterlib
• Leopard
• Toauta
• Tron
• Wuca
• Rifbu
• Wgapatch
• Cobra

Machine-readable

Get this profile as JSON: https://malware-families-catalog.systemhelpdesk.com/api/sillyp2p.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.