Skypespam

Overview

Worm:Win32/Skypespam is a heuristic classification for worms and trojans that specifically target the Skype messaging platform to aggressively self-replicate by sending malicious links to all contacts in the victim's address book.

Understanding Skypespam
To the victim, a Skypespam infection results in their Skype account rapidly sending out messages containing deceptive links (e.g., 'lol is this you in this video? [link]') to their friends and colleagues. For incident responders, it is a localized worm that leverages social engineering and the implied trust of instant messaging to achieve high infection rates.

Execution and Evasion Strategies
The infection cycle begins when a user clicks a malicious link received via Skype. The link typically leads to a compromised website that downloads a dropper payload (often disguised as an image or video codec). Upon execution, the malware utilizes the Skype Desktop API (or injects into the `skype.exe` process) to programmatically access the user's contact list and send the localized spam message. The malware establishes persistence via Registry Run keys and frequently downloads secondary payloads, such as cryptocurrency miners or infostealers, to monetize the infected host.

Indicators of Compromise & Impact
The impact is rapid lateral movement (socially), reputational damage, and the execution of secondary payloads. Threat hunters will observe anomalous child processes spawned by `skype.exe`. EDR platforms frequently flag Skypespam for its aggressive API hooking or process injection targeting the messaging client. Network logs will show the endpoint reaching out to known malicious URL shorteners or compromised domains to download the secondary payloads.

MITRE ATT&CK Techniques

Observed techniques used by this family, mapped to the 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.
• T1566.002: Inspect email links for known malicious domains and use link-rewriting services for time-of-click analysis.

Generated Detections (Boilerplate)

These YARA and Sigma rules are auto-generated based on the family name and aliases. They must be heavily tuned before deployment in a production environment.

YARA Rule

rule MALWARE_WIN_SKYPESPAM {
    meta:
        description = "Detects Skypespam (trojan)"
        author = "SystemHelpdesk Boilerplate Generator"
        date = "2026-07-06"
    strings:
        $s1 = "skypespam" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

Sigma Rule

title: Suspicious Skypespam Activity
id: 79800ae60203029b1cf5073e4ae8f958
status: experimental
description: Detects generic indicators of the skypespam malware family.
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\cmd.exe'
            - '\powershell.exe'
        CommandLine|contains:
            - "*skypespam*"
    condition: selection
level: medium

Containment & Response Steps

Ordered checklist for responders. Adapt to your environment and engage professional support for active incidents.

1. Isolate the endpoint to halt the active spam campaign and prevent the downloading of further secondary payloads.
2. Advise the victim to immediately change their Skype password and enable Multi-Factor Authentication (MFA).
3. Utilize EDR to identify and terminate the specific malicious process hooking into the Skype API.
4. Perform a full forensic sweep to identify and remove the core worm executable and any secondary payloads (like miners) it downloaded.

What to Avoid

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

1. Do not ignore the infection as a 'low severity' spam issue; the worm frequently downloads high-severity trojans as secondary payloads.
2. Avoid relying solely on automated AV removal; ensure the user's Skype account credentials are changed to prevent cloud-based account hijacking.

References & External Analysis

• Search "skypespam" on VirusTotal (External Analysis)

Frequently Asked Questions

Related Families (Category: trojan)

Explore other malware families in the same category:

• Prorat
• Kjwar5Ju8Ibgb
• Kwampirs
• Faketool
• Exxroute

Machine-readable

Get this profile as JSON: https://jordan123234-malware-families-explorer.static.hf.space/api/skypespam.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.