hacker-news · Crawled Jul 30, 2026

Russian Hackers Exploit Microsoft OWA Flaw to Keep Mailbox Access After Credential Rotation

1 IoCs 1 Actors 1 CVEs
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AI Summary

Russian threat actor TA488, also known as Laundry Bear, has exploited CVE-2026-42897, a cross-site scripting (XSS) vulnerability in Microsoft Outlook Web Access (OWA), to conduct cyber espionage against U.S. and European government entities, as well as organizations in the telecommunications, financial, hospitality, and aerospace sectors. The attacks use 'half-click' phishing emails sent from compromised or Proton Mail accounts, which trigger a JavaScript-based payload called OWAReaper upon viewing. This browser-based implant enables persistent access to mailboxes by leveraging server-side persistence mechanisms, surviving credential rotation and device re-imaging. OWAReaper uses GitHub and email for command-and-control, exfiltrates data via encrypted HTTPS or DNS tunneling, and maintains access by stealing OAuth tokens and granting itself Owner-level permissions on mail folders.

AI-extracted · verify before operational use

Extracted Entities 2 found

Threat Actor Void Blizzard → CVE CVE-2025-66376 →

Indicators of Compromise 1 extracted

Type Value Detail
Domain protonmail[.]com Details →

MITRE ATT&CK TTPs 39 techniques

T1003 OS Credential Dumping · Credential Access T1003.001 LSASS Memory · Credential Access T1021.003 Distributed Component Object Model · Lateral Movement T1027 Obfuscated Files or Information · Defense Evasion T1055 Process Injection · Defense Evasion T1056.001 Keylogging · Collection T1059.001 PowerShell · Execution T1059.003 Windows Command Shell · Execution T1059.007 JavaScript · Execution T1070.004 File Deletion · Defense Evasion T1071 Application Layer Protocol · Command And Control T1071.001 Web Protocols · Command And Control T1071.003 Mail Protocols · Command And Control T1071.004 DNS · Command And Control T1074.001 Local Data Staging · Collection T1080 Taint Shared Content · Lateral Movement T1082 System Information Discovery · Discovery T1083 File and Directory Discovery · Discovery T1090 Proxy · Command And Control T1098 Account Manipulation · Persistence T1105 Ingress Tool Transfer · Command And Control T1110 Brute Force · Credential Access T1114 Email Collection · Collection T1132.002 Non-Standard Encoding · Command And Control T1190 Exploit Public-Facing Application · Initial Access T1203 Exploitation for Client Execution · Execution T1204.002 Malicious File · Execution T1485 Data Destruction · Impact T1496 Resource Hijacking · Impact T1530 Data from Cloud Storage · Collection T1539 Steal Web Session Cookie · Credential Access T1552 Unsecured Credentials · Credential Access T1555 Credentials from Password Stores · Credential Access T1557 Adversary-in-the-Middle · Credential Access T1558.003 Kerberoasting · Credential Access T1566 Phishing · Initial Access T1568 Dynamic Resolution · Command And Control T1570 Lateral Tool Transfer · Lateral Movement T1588 Obtain Capabilities · Resource Development