Harvester
Overview
Executive Summary
Harvester (often detected as Spyware.Harvester or Trojan.Harvester) is a highly specialized info-stealer malware engineered specifically to target, aggregate, and extract sensitive data from compromised Windows endpoints. Unlike generic droppers, Harvester's primary objective is immediate espionage: it actively scrapes the file system and intercepts communications to harvest user credentials, financial information, and valuable intellectual property.Infection Vector and Technical Capabilities
Harvester is typically distributed via highly targeted spear-phishing campaigns containing weaponized attachments or delivered as a secondary payload by an initial access broker. Once executed, the malware focuses entirely on data aggregation:- Browser Profiling and Cookie Theft: Harvester aggressively targets nearly all modern web browsers (Chrome, Firefox, Edge). It extracts saved passwords, autofill data, credit card numbers, and critically, active session cookies (allowing attackers to bypass MFA).
- File System Scraping: The malware often includes a module to recursively scan the local hard drive and attached network shares for files matching specific extensions (e.g., `.docx`, `.pdf`, `.kdbx` for password vaults) or containing specific keywords (e.g., "password", "finance").
- Data Exfiltration: The stolen data is aggregated into hidden, encrypted ZIP archives on the local disk. It is then periodically transmitted back to the C2 server over standard web ports (HTTPS) or via FTP to evade deep packet inspection.
Threat Assessment
A Harvester infection is a critical security breach resulting in immediate and ongoing data loss. The exfiltrated credentials can be used to compromise the user's personal accounts, pivot laterally across the corporate network, or access sensitive cloud infrastructure without triggering brute-force alerts.Incident Response and Remediation
- Immediate Isolation: Sever the affected machine's network connection immediately to halt any active or pending data exfiltration.
- Comprehensive Credential Reset: Assume all credentials typed or saved on the infected machine since the time of infection are fully compromised. Initiate an immediate, organization-wide password reset for the affected user, and invalidate all active session tokens.
- Forensic Analysis: Conduct a forensic review of the endpoint to determine the initial vector of compromise and to ensure Harvester did not deploy secondary backdoors prior to detection.
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 T1539 T1048 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_HARVESTER {
meta:
description = "Detects Harvester (trojan)"
author = "SystemHelpdesk Boilerplate Generator"
date = "2026-07-06"
strings:
$s1 = "harvester" ascii wide nocase
$s2 = "trojan.harvester" ascii wide nocase
$s3 = "spyware.harvester" ascii wide nocase
$s4 = "pws.win32.harvester" ascii wide nocase
condition:
uint16(0) == 0x5a4d and any of them
}Sigma Rule
title: Suspicious Harvester Activity
id: 9f8f961b5607b1003cf830f44c67efc9
status: experimental
description: Detects generic indicators of the harvester malware family.
logsource:
category: process_creation
product: windows
detection:
selection:
Image|endswith:
- '\cmd.exe'
- '\powershell.exe'
CommandLine|contains:
- "*harvester*"
- "*trojan.harvester*"
- "*spyware.harvester*"
- "*pws.win32.harvester*"
condition: selection
level: mediumReferences & External Analysis
- Search "harvester" on VirusTotal (External Analysis)
Frequently Asked Questions
How do I remove the Harvester Trojan from Windows?
Manual removal of Harvester 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 Harvester a virus or a Trojan?
Harvester is classified as a Trojan. Unlike traditional viruses that infect files, modern malware like Harvester typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.
What are the main symptoms of a Harvester infection?
Symptoms of Harvester 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 Harvester and similar threats from compromising your organization? Read our comprehensive defensive guide: Banking Trojan Protection.
Machine-readable
Get this profile as JSON: https://jordanricky1604-ship-it.github.io/malware-families-catalog/api/harvester.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.