Keylogr
Overview
Executive Summary
"Keylogr" is a generic detection name used by security engines to identify software that exhibits the behavioral characteristics of a keystroke logger. Whether it is a commercial "employee monitoring" tool (Riskware) or a malicious, custom-built Info Stealer (Trojan), its primary function is to silently record every keystroke made by the user, posing a critical threat to credential security and data confidentiality.Infection Vector and Technical Capabilities
Malicious keyloggers are typically deployed via targeted spear-phishing (malicious attachments), drive-by downloads, or dropped by initial access brokers who have compromised a system. Commercial (Riskware) keyloggers must be installed manually by someone with physical access or administrative rights. Regardless of the source, Keylogr variants utilize deep system monitoring:- API Hooking: The most common technique involves hooking core Windows APIs (such as `SetWindowsHookEx` or `GetAsyncKeyState`). This allows the software to intercept hardware interrupts from the keyboard before the keystrokes are passed to the active application.
- Kernel-Level Logging: More advanced variants operate as kernel-mode rootkits, intercepting keystrokes at the driver level (`kbdclass.sys`). This makes them completely invisible to user-mode security software and the Windows Task Manager.
- Data Exfiltration: The captured keystrokes (which inevitably include passwords, emails, and sensitive communications) are saved to hidden, encrypted log files. These logs are then periodically exfiltrated to the attacker via SMTP, FTP, or HTTP POST requests.
Threat Assessment
The detection of a Keylogr is a critical security incident. It guarantees the compromise of any password or sensitive data typed on the infected machine. This provides attackers with the credentials necessary to escalate privileges, access corporate VPNs, and pivot laterally across the network.Incident Response and Remediation
- Immediate Network Isolation: The highest priority is to disconnect the infected endpoint from the network to halt the active exfiltration of the keystroke logs.
- Global Credential Reset: It must be assumed that *all* passwords typed on the machine have been stolen. A mandatory, immediate reset of all associated enterprise credentials is required.
- Complete Re-imaging: Due to the deep system hooking (often at the kernel level) used by keyloggers, attempting to "clean" the machine manually is highly risky and often ineffective. A complete bare-metal wipe and re-image from a trusted baseline is necessary.
Known aliases
Threat reports may refer to this family under multiple names:
MITRE ATT&CK Techniques
This family has been observed using the following ATT&CK techniques: T1056.001 T1115 T1552.001
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.
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_KEYLOGR {
meta:
description = "Detects Keylogr (trojan)"
author = "SystemHelpdesk Boilerplate Generator"
date = "2026-07-06"
strings:
$s1 = "keylogr" ascii wide nocase
$s2 = "trojan.keylogger" ascii wide nocase
$s3 = "spyware.keylog" ascii wide nocase
$s4 = "riskware.monitor" ascii wide nocase
condition:
uint16(0) == 0x5a4d and any of them
}Sigma Rule
title: Suspicious Keylogr Activity
id: a87324818dd754214cab2e3574e27329
status: experimental
description: Detects generic indicators of the keylogr malware family.
logsource:
category: process_creation
product: windows
detection:
selection:
Image|endswith:
- '\cmd.exe'
- '\powershell.exe'
CommandLine|contains:
- "*keylogr*"
- "*trojan.keylogger*"
- "*spyware.keylog*"
- "*riskware.monitor*"
condition: selection
level: mediumReferences & External Analysis
- Search "keylogr" on VirusTotal (External Analysis)
Frequently Asked Questions
How do I remove the Keylogr Trojan from Windows?
Manual removal of Keylogr is highly discouraged as it may leave persistence mechanisms intact. We recommend disconnecting the device from the internet and utilizing a professional incident response service or enterprise-grade EDR software to conduct a full forensic sweep.
Is Keylogr a virus or a Trojan?
Keylogr is classified as a Trojan. Unlike traditional viruses that infect files, modern malware like Keylogr typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.
What are the main symptoms of a Keylogr infection?
Symptoms of Keylogr can include unexpected system slowness, unauthorized outbound network traffic to unknown IP addresses, disabled security software, and suspicious background processes running from AppData or Temp directories.
Related Families (Category: trojan)
Explore other malware families in the same category:
Protect Your Network Against Trojans
Want to prevent Keylogr and similar threats from compromising your organization? Read our comprehensive defensive guide: Banking Trojan Protection.
Machine-readable
Get this profile as JSON: https://jordan123234-malware-families-explorer.static.hf.space/api/keylogr.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.