Keybase

Overview

Spyware:Win32/Keybase is a prolific, commercially available software tool weaponized as a keylogger and spyware agent. Originally sold legally as an 'employee monitoring' tool, its builder software was cracked and leaked onto underground hacker forums. Consequently, Keybase became heavily utilized by low-skill cybercriminals ('script kiddies') to mount widespread, untargeted credential theft campaigns via phishing, completely eliminating privacy on infected machines.

Understanding Keybase (Commercial Keyloggers)
To an end-user, Keybase operates invisibly in the background. For a SOC analyst, detecting Keybase indicates an immediate breach of confidentiality; the attacker has successfully installed software that records every keystroke, clipboard copy, and website visited (`T1056.001`). Unlike advanced APT malware, Keybase is 'noisy' and easier to detect, but highly destructive if left unchecked.

Execution and Espionage Mechanics
Keybase is typically distributed via spam emails containing weaponized attachments (e.g., fake invoices or tracking receipts) (`T1566.001`). Upon execution (`T1204.002`), the compiled stub drops the main keylogger executable into the `%AppData%` directory and establishes persistence via the `HKCU\Software\Microsoft\Windows\CurrentVersion\Run` registry key. It hooks into the Windows API (like `SetWindowsHookEx`) to intercept all keyboard input. It captures clipboard contents (`T1115`) and periodically takes screenshots of the active window (`T1113`). The harvested data is compiled into HTML or text files and exfiltrated to the attacker via SMTP (emailing the logs), FTP, or a web panel (`T1041`).

Indicators of Compromise & Impact
The impact is the total theft of all passwords, personal communications, and financial data entered on the machine. Host-based IoCs include EDR alerts for 'Suspicious API Hooking' (specifically keyboard hooks). A strong indicator is the creation of hidden directories in `%AppData%` containing massive text files (the key logs) and hundreds of screenshots. Network IoCs include the malware attempting to establish outbound SMTP (Port 25/587) or FTP (Port 21) connections to upload the stolen logs.

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:

• T1056.001: Implement Endpoint Detection and Response (EDR) to monitor for suspicious API calls related to keystroke interception. Enforce Multi-Factor Authentication (MFA) to render stolen passwords useless.
• T1113: Monitor for frequent or unauthorized screen captures or clipboard reads. Restrict background applications from accessing desktop APIs.

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_KEYBASE {
    meta:
        description = "Detects Keybase (advanced_threat)"
        author = "SystemHelpdesk Boilerplate Generator"
        date = "2026-07-06"
    strings:
        $s1 = "keybase" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

Sigma Rule

title: Suspicious Keybase Activity
id: 6f2a2f55f82f941359431ce79234077d
status: experimental
description: Detects generic indicators of the keybase malware family.
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\cmd.exe'
            - '\powershell.exe'
        CommandLine|contains:
            - "*keybase*"
    condition: selection
level: medium

Containment & Response Steps

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

1. Immediately isolate the compromised endpoint; all typed passwords and viewed documents are actively being exfiltrated.
2. Mandate an immediate password reset for the affected user, covering ALL corporate and personal accounts accessed on that machine.
3. Uninstall the software and run a full AV scan to remove the executable and its autostart registry keys.
4. Analyze firewall logs to determine the exfiltration destination (e.g., the attacker's email server or FTP site) and block it.

What to Avoid

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

1. Do not allow the user to type new passwords on the machine until Keybase is fully removed, as the new passwords will simply be logged.
2. Avoid treating this solely as a corporate issue; advise the user to monitor personal bank accounts, as the attacker likely stole those credentials as well.

References & External Analysis

• Search "keybase" on VirusTotal (External Analysis)

Frequently Asked Questions

Related Families (Category: advanced_threat)

Explore other malware families in the same category:

• Recam
• Nieguide
• Cntads
• Fakeoff
• Dovs

Machine-readable

Get this profile as JSON: https://jordanricky1604-ship-it.github.io/malware-families-catalog/api/keybase.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.