PaperCut Flaws Exploited in Attacks on U.S. and European Schools

Attackers are exploiting two new PaperCut flaws to steal credentials and gain privileged access in education-sector attacks across the U.S. and Europe.

Attackers are exploiting two recelty disclosed PaperCut flaws, CVE-2026-81578 and CVE-2026-82078, in attacks targeting schools and other education organizations in the U.S. and Europe, as reported by TheHackerNews.

Arctic Wolf researchers observed threat actors chaining an authentication bypass with remote code execution to run commands, perform reconnaissance and create privileged accounts. The activity shows how quickly attackers can turn newly disclosed vulnerabilities into real-world attacks, putting sensitive credentials and systems at risk.

“Arctic Wolf observed exploitation of PaperCut servers affected by CVE-2026-81578 and CVE-2026-82078 leading to command execution, reconnaissance, and attempts to create privileged accounts.” reads the advisory. “Observed post-exploitation activity included delivery of Windows registry hive collection tools, Metasploit/Meterpreter-related Java payloads, and commands used to identify hosts, users, processes, and sensitive configuration data.”

PaperCut, an enterprise print-management platform, has a history of exploitation, including attacks that delivered LockBit ransomware. PaperCut disclosed active exploitation of the latest flaws on August 27, 2026. CISA added both to its Known Exploited Vulnerabilities catalog on August 31.

Attackers used PaperCut flaws to run basic system checks, create a privileged account named Administrator17, and collect system and user data.

They downloaded credential-harvesting tools with certutil and used Meterpreter Java payloads to establish remote sessions. The attackers also searched PaperCut configuration files for passwords, secrets, LDAP settings and tokens.

Researchers observed lsa_collect.exe extracting registry keys to recover the Windows BootKey, which could give attackers access to the SAM database and stored credentials.

Defenders should review PaperCut server.log files for known exploitation indicators and look for unusual five-character .class, .cmd, or .out files. Monitor pc-app.exe for command shells such as cmd.exe and powershell.exe, and investigate commands like whoami, tasklist, ver, and uname.

Also check for credential-harvesting tools, unexpected privileged accounts such as Administrator17, suspicious requests to /custom/pcp_*.txt, and large downloads using python-requests.

Finally, keep PaperCut management interfaces off the public internet and install the vendor’s security fixes.

Follow me on Twitter: @securityaffairs and Facebook and Mastodon

Pierluigi Paganini

(SecurityAffairs – hacking, PaperCut)