HOMETHREATSISR Stealer
APT / THREAT GROUP

ISR Stealer

2
aliases
Last seen:Mar 17, 2026

Intelligence Profile

ISR Stealer is a modified version of the Hackhound Stealer. It is written in VB and often comes in a .NET-wrapper.

ISR Stealer makes use of two Nirsoft tools: Mail PassView and WebBrowserPassView.

Incredibly, it uses an hard-coded user agent string: HardCore Software For : Public

Threat Analysis

ISR Stealer is a known-sophistication threat actor of undetermined national origin, engaged in cyber operations with a primary motivation of unknown activity patterns.

External References

→https://securingtomorrow.mcafee.com/mcafee-labs/phishing-attacks-employ-old-effective-password-stealer/

Quick Facts

TypeAPT / Threat Group
Aliases2

Also Known As

win.isr_stealerISR Stealer

External Intelligence

Malpedia: win.isr_stealer

Research Links

MITRE ATT&CK VirusTotal Google (news) Twitter/X search
Data sourced from Malpedia, Ransomware.live, RansomLook, and CTIWATCH OSINT collection. Actor attribution is based on available intelligence and may be incomplete.
← All Threat Actors·Geopolitics Map·Search ISR Stealer