Data Breaches & Leaks Unit 42 1 month ago

Threat Brief: Mitigating Large-Scale Credential Attacks (Updated August 18)

CN
CyberNew Threat Research Desk
• Original Reporting: Unit 42
CyberNew Threat Intel Assessment
Assessed Severity: INFORMATIONAL
Impacted Surface
Enterprise Data & Identity Stores
Intelligence Sector
Data Breaches & Leaks

Analyst Takeaway

"Executive Summary Identity has effectively become the new perimeter, where cybercriminals are increasingly choosing to log in rather than break in. To accomplish this, attackers frequently gather previously leaked username and password pairs. Gathering these credentials can then allow them to pivot to password spraying against services exposed to the internet, gaining credentials for other..."

Recommended Defense & Mitigation

  • Threat Monitoring: Ingest published IOCs into SIEM/EDR detection rules for continuous telemetry monitoring.
  • Security Awareness: Alert staff and maintain baseline endpoint hardening across endpoints.
Curated & Verified by CyberNew Threat Intelligence Desk Standard Defense Framework (NIST / MITRE ATT&CK)

Executive Summary

Identity has effectively become the new perimeter, where cybercriminals are increasingly choosing to log in rather than break in. To accomplish this, attackers frequently gather previously leaked username and password pairs. Gathering these credentials can then allow them to pivot to password spraying against services exposed to the internet, gaining credentials for other products and services.

As this sort of attack occurs frequently, this article will be a resource repository of the following information about these attacks:

  • Details of noteworthy large scale credential attacks 
  • Actionable guidance for mitigating these attacks

TheHatman Attack

  • The Hatman attack: In August 2026, the actor TheHatman claimed to have stolen large volume of credentials from organizations' Microsoft Entra tenants

FortiBleed Attack

  • Fortibleed Credential Campaign: In June 2026, there was a large-scale password spraying campaign targeting Fortinet devices

Unit 42 recommends auditing remote access logs for suspicious activity with a focus on successful logins shortly after large volume password failure events. We also recommend reviewing and implementing the hardening guidance in this article for edge devices. 

Palo Alto Networks customers are better protected from this activity through our products and services, such as:

The Unit 42 Incident Response team can also be engaged to help with a compromise or to provide a proactive assessment to lower your risk.

Related Unit 42 Topics Fortibleed, Credential Theft

Activity From TheHatman

Source Verification & Original Intelligence

This threat report was reviewed by CyberNew analysts and cross-referenced with primary security disclosures from Unit 42.

Primary Advisory →