Hackers Turn Windows Shadow Copies Into a Tool for Credential Theft and Ransomware
Attackers abuse Windows VSS shadow copies to delete recovery points before ransomware and to extract NTDS.dit/SAM credentials, demanding context-aware detection.
Threat actors are weaponizing the Volume Shadow Copy Service (VSS) for two purposes: destroying local recovery points via vssadmin.exe, wmic.exe, diskshadow.exe, wbadmin.exe, and bcdedit.exe before encryption, and accessing static copies of locked files such as NTDS.dit and SAM for credential theft. Ransomware families tied to shadow-copy removal include Akira, Black Basta, BlackCat, Conti, LockBit, Qilin, RansomHub, REvil, Ryuk, and WannaCry. Huntress's analysis of the Nightmare-Eclipse tool showed the BlueHammer technique chaining a Windows Defender timing issue with a VSS snapshot to dump the SAM database and decrypt NT hashes. Defenders should correlate VSS operations with parent process, hive access, and subsequent encryption activity, and maintain immutable off-host backups.
PaperCut Flaws Exploited in Attacks on U.S. and European Schools
Attackers are chaining recently disclosed PaperCut flaws CVE-2026-81578 and CVE-2026-82078 to steal credentials and create privileged accounts at US and European schools.
Arctic Wolf researchers observed threat actors exploiting PaperCut servers via CVE-2026-81578 and CVE-2026-82078, chaining an authentication bypass with remote code execution. Post-exploitation included creating a privileged account named Administrator17, downloading credential-harvesting tools with certutil, Meterpreter Java payloads, and registry hive collection to recover the Windows BootKey and reach the SAM database. PaperCut disclosed active exploitation on August 27, 2026, and CISA added both flaws to its Known Exploited Vulnerabilities catalog on August 31. PaperCut has a history of exploitation, including attacks that delivered LockBit ransomware.
Attackers plant remote access tools on compromised PaperCut servers
Attackers chained two PaperCut NG/MF zero-days for unauthenticated access, installing SimpleHelp and AnyDesk remote access tools on compromised servers.
An ongoing campaign exploits chained zero-days CVE-2026-81578 (improper access control) and CVE-2026-82078 (unsafe dynamic class loading) in internet-facing PaperCut NG and MF Application Servers, enabling authentication bypass and arbitrary Java bytecode execution. Post-compromise activity includes user and domain enumeration, payload download from sendit.sh, and silent installation of SimpleHelp and AnyDesk for redundant remote access; Defused observed CVE-2026-81578/CVE-2026-82078 exploit activity in honeypots since August 29, including data theft via Derby database dumps. Emergency patches were released August 28 and August 30, but 47% of roughly 2,500 PaperCut installs tracked by Huntress run v23 or older, for which no patch is available.
PaperCut NG/MF vulnerabilities exploited in zero-day attacks
PaperCut warns of active zero-day exploitation chaining CVE-2026-81578 and CVE-2026-82078 for pre-auth remote code execution in NG/MF print management.
PaperCut Software confirmed attackers are chaining two vulnerabilities in PaperCut NG and MF: CVE-2026-81578, an improper access control flaw in the web management interface allowing unauthenticated configuration changes, and CVE-2026-82078, unsafe dynamic class loading in database connection utilities enabling arbitrary Java bytecode execution. Huntress reproduced a pre-authentication remote configuration takeover and full RCE chain against PaperCut NG 25.0.11.75758 and observed limited exploitation at two customers, including post-exploitation whoami and ver commands. The vendor released Emergency Patch Release 2 with additional hardening and urged restricting Application Server web access to trusted IPs. In 2023, Clop and LockBit affiliates abused CVE-2023-27350 and CVE-2023-27351 in the same software.
PaperCut Zero-Day Exploited in Attacks, Affecting All NG and MF Versions
PaperCut warns of actively exploited zero-day RCE chain CVE-2026-81578 and CVE-2026-82078 affecting all PaperCut NG and MF versions.
PaperCut alerted customers that attackers are actively exploiting a zero-day affecting all versions of PaperCut NG and MF print management software, with confirmed customer incidents and an ongoing investigation. Emergency patches were released for v25 and v26, and the flaw was later identified as an exploitation chain of CVE-2026-81578 and CVE-2026-82078 enabling remote code execution. Shared IoCs include suspicious post-exploitation activity from pc-app.exe and missing, truncated or deleted server.log files with specific database errors. Users with internet-exposed PaperCut Application Servers are urged to immediately restrict access to trusted IPs; in 2023, CVE-2023-27350 (CVSS 9.8) in the same products was exploited by Lace Tempest to deliver Cl0p and LockBit ransomware.
ExfilSquad Targets New Victims, Shares Data via Torrents
Extortion group ExfilSquad lists 13 new US, UK and Swedish victims and now distributes stolen data via peer-to-peer torrents.
ExfilSquad, a data-theft extortion collective that emerged in mid-2026, announced 13 new victims in the US, UK and Sweden with an August 5, 2026 negotiation deadline. The group skips ransomware, instead stealing data and threatening publication on a dark web leak site. Resecurity says its TTPs center on exploiting misconfigured Microsoft Dataverse, Power Pages, case management and CRM portals. The group now distributes stolen data through per-victim torrent trackers and web seeds, making leaks hard to contain.