{ "family": "perflogger", "sample_count": 11, "category": "trojan", "description": "Spyware:Win32/Perflogger is a covert surveillance tool and keylogger designed to secretly record user activity, capture keystrokes, monitor clipboard contents, and exfiltrate sensitive data (such as passwords, financial details, and personal communications) to a remote attacker.

Understanding Perflogger
To the victim, Perflogger operates entirely invisibly, with no outward signs of infection aside from a potential, minor decrease in system performance. For security analysts, a keylogger represents an immediate and total compromise of user credentials and sensitive data. Perflogger is often deployed as a secondary payload by a dropper trojan, or installed manually by an attacker who has already gained initial access.

Execution and Data Capture Mechanics
Perflogger typically establishes persistence via Registry Run keys (`T1547.001`) to ensure it starts immediately upon user login. To capture data, it relies heavily on native Windows API hooking. It utilizes `SetWindowsHookEx` to intercept keyboard input globally across all applications (`T1056.001`). It may also periodically capture screenshots (`T1113`) and monitor the system clipboard for copied passwords (`T1115`). The stolen data is temporarily stored locally in hidden, encrypted log files (`T1005`) before being bundled and exfiltrated to a C2 server via FTP, SMTP (email), or HTTP POST requests (`T1041`).

Indicators of Compromise & Impact
The primary impact is identity theft, credential compromise, and data breach. Incident responders should monitor EDR for suspicious processes injecting DLLs to hook input APIs, or processes frequently reading the clipboard. A strong IoC is an unknown executable in `%AppData%` generating small, steadily growing, heavily obfuscated log files and occasionally sending them outbound over FTP or SMTP.", "cta": "Published by the SystemHelpdesk team.", "aliases": [], "enrichment_level": "expert-seo", "faq": [ { "@type": "Question", "name": "What is Perflogger and what threat category does it belong to?", "acceptedAnswer": { "@type": "Answer", "text": "Perflogger is classified as a Trojan. Documented across security telemetry, it is engineered to execute unauthorized operations, establish persistent footholds on target endpoints, and facilitate malicious campaigns targeting enterprise and individual environments." } }, { "@type": "Question", "name": "How does Perflogger establish persistence and evade defensive controls?", "acceptedAnswer": { "@type": "Answer", "text": "Perflogger typically establishes persistence through registry run keys, scheduled tasks, or service installations, while evading signature-based antivirus solutions through code obfuscation, memory injection, or anti-analysis sandbox checks." } }, { "@type": "Question", "name": "What are the essential incident response steps for mitigating a Perflogger compromise?", "acceptedAnswer": { "@type": "Answer", "text": "Security teams responding to Perflogger should immediately isolate affected endpoints from the network, perform memory triage to capture volatile forensic artifacts, audit registry and startup persistence mechanisms, revoke exposed user credentials, and restore systems from verified, clean backups." } }, { "@type": "Question", "name": "What secondary payloads and staging behaviors are commonly associated with Perflogger?", "acceptedAnswer": { "@type": "Answer", "text": "Perflogger frequently operates as a loader or dropper designed to establish a foothold before downloading and executing secondary high-impact malware payloads. Depending on the threat actor's objectives, these dropped modules can range from ransomware and banking injects to modular infostealers and remote management backdoors." } }, { "@type": "Question", "name": "How can security operations teams effectively detect and hunt for Perflogger across enterprise endpoints?", "acceptedAnswer": { "@type": "Answer", "text": "Defenders should hunt for Perflogger by deploying behavioral endpoint detection and response (EDR) rules that monitor suspicious process spawning (such as cmd.exe or powershell.exe spawned from office documents or temporary directories), anomalous outbound network connections from non-browser binaries, and unauthorized modifications to Windows Run keys and scheduled task registries." } } ], "faq_count": 5, "mitre_attack": [ "T1115", "T1056.001", "T1113", "T1547.001", "T1041" ], "cisa_advisory": null, "last_updated": "2026-06-09", "mitre_attack_detail": [ { "id": "T1056.001", "name": "Input Capture: Keylogging", "tactic": "Credential Access" }, { "id": "T1115", "name": "Clipboard Data", "tactic": "Collection" }, { "id": "T1113", "name": "Screen Capture", "tactic": "Collection" }, { "id": "T1041", "name": "Exfiltration Over C2 Channel (FTP/SMTP)", "tactic": "Exfiltration" }, { "id": "T1547.001", "name": "Boot or Logon Autostart Execution: Registry Run Keys", "tactic": "Persistence" } ], "containment_steps": [ "Assume all passwords typed on the infected machine, as well as all active session cookies, have been compromised. Enforce immediate resets.", "Isolate the endpoint from the network to halt the active exfiltration of the recorded keylog files.", "Use EDR to track down the hidden executable responsible for the hooking, and locate the local staging directory where the keylogs are stored.", "Terminate the keylogger process and remove its persistence mechanisms from the Registry." ], "what_to_avoid": [ "Do not assume Multi-Factor Authentication (MFA) will fully protect the user; keyloggers often capture the MFA tokens as they are typed, and some capture session cookies.", "Avoid delaying the password reset process; the data is usually exfiltrated rapidly." ], "target_industries": [ "Global / Opportunistic" ], "motivation": "Opportunistic", "threat_actors": [ "Unknown / Cybercriminal" ], "target_geographies": [ "Global" ], "attack_stage": [ "execution", "persistence" ], "ecosystem": [ "windows_pe" ], "is_emerging": false, "target_platforms": [ "Windows 11", "Windows 10", "Windows 7" ] }