ISR Stealer

Internal ID: win.isr_stealer

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 malware family tracked by threat intelligence researchers and catalogued in the Malpedia dataset. It represents a distinct malicious software lineage with identifiable code characteristics, behaviors, and victimology.

External References

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

Quick Facts

TypeMalware Family

Aliases1

Also Known As

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