Oracle PeopleSoft PeopleTools

The initial-access vector that was attacker-asserted yesterday is now vendor-confirmed: Oracle assigned CVE-2026-35273 (CVSS 9.8), an unauthenticated RCE in the PeopleTools Environment Management Hub (PSEMHUB, versions 8.61/8.62), and published an out-of-band Security Alert with fixes (Oracle, 2026-06-10; SecurityWeek, 2026-06-11).

Mandiant GTIG formally attributes the campaign to UNC6240 (ShinyHunters), dating exploitation 27 May – 9 June (a zero-day for the full window) and details the post-exploitation chain: customised MeshCentral remote-management agents masquerading as Microsoft Azure components for persistence and C2, and a per-victim _fanout.sh lateral-movement script spraying SSH credentials against internal hosts harvested from /etc/hosts (T1190, T1021.004). Mandiant notified more than 100 organisations with exposed PSEMHUB endpoints; 68 % are higher-education institutions (Mandiant GTIG, 2026-06-11).

The University of Nottingham (confirmed as a victim yesterday) now quantifies the damage: roughly 40 GB exfiltrated covering ~455,000 individuals across its UK, Malaysia and China campuses, including names, contact details, ethnicity, disability, passport and tuition-payment data; the ICO says it is assessing the report (BleepingComputer, 2026-06-11; The Record, 2026-06-11; University of Nottingham, 2026-06-10). Action: see the § 0 callout, patch out-of-band and compromise-assess; yesterday's hardening guidance (default SSH service accounts, PSEMHUB exposure) stands.

Mandiant and Google GTIG formally attribute the PeopleSoft Environment Management Hub exploitation campaign to UNC6240 (ShinyHunters) and confirm the activity ran from 27 May to 9 June 2026, predating Oracle's 10 June out-of-band advisory, establishing CVE-2026-35273 (CVSS 9.8) as a zero-day at time of exploitation (Mandiant/GTIG, 2026-06-11). The unauthenticated SSRF→RCE is reached via the /PSEMHUB/hub and /PSIGW/HttpListeningConnector endpoints in PeopleTools 8.61/8.62.

GTIG notified over 100 organisations whose endpoints correlated with exploitation; 68% are higher-education institutions. Post-exploitation, the actor deployed MeshCentral remote-management agents disguised as Azure binaries, used SSH fan-out scripts with PeopleSoft admin credentials for lateral movement, and exfiltrated to the ShinyHunters leak site (Rapid7, 2026-06-12). The University of Nottingham confirmed 454,600 student and alumni records were taken, including passport numbers (University of Nottingham; BleepingComputer, 2026-06-11). CISA added the CVE to KEV on 12 June. Swiss/EU universities running Campus Solutions should treat this as P1 (.

ShinyHunters listed the Council of Europe (the 46-member Strasbourg human-rights body, of which Switzerland is a member) claiming 297 GB across ~429,000 files taken via the Oracle PeopleSoft Environment Management Hub zero-day CVE-2026-35273, and set a 16 June leak deadline (SecurityWeek, 2026-06-15). This is the first European intergovernmental institution named in the 100+-organisation PeopleSoft campaign previously covered as an education-sector wave.

The claimed dataset spans payroll for 10,000+ current and former staff (2011–2026), 14,000+ CVs, and HR records with names, dates of birth, addresses, bank-account, tax/social-security and medical data. The Council of Europe confirmed it "is currently investigating the matter and assessing the situation" and has not confirmed exfiltration (The Register, 2026-06-15; BleepingComputer, 2026-06-15). The vector, unauthenticated HTTP to the /PSEMHUB/hub servlet (T1190), is unchanged; treat any externally-reachable PeopleSoft Environment Management Hub as compromised pending forensic review and block perimeter access to /PSEMHUB/*. Confidence on the victim claim is MEDIUM pending Council of Europe confirmation (extortion-site claim).

Mandiant and GTIG report that UNC6240 (ShinyHunters) has resumed mass exploitation of CVE-2026-35273, adapting to the defensive guidance this campaign's own earlier coverage carried. The actor now bypasses WAF rules that block the literal /PSEMHUB/ path by requesting the URL-encoded /%50SEMHUB/ instead: many WAFs and reverse proxies match the request path before decoding it, while the PeopleSoft application server decodes and routes the request normally. "This allows the threat actor to reach the endpoint on systems whose operators may have believed their WAF rules had mitigated the exposure" (Mandiant/GTIG, 2026-09-25). Mandiant warns the actor may rotate to other percent-encoded, mixed-case or otherwise non-normalized path variants, so defenders should block on the normalized path rather than the literal string.

Before exploiting a target, the actor sends five to fifteen POST requests carrying a serialized Java object to quietly confirm exploitability without writing files or disrupting the service. Two complementary single-line JSP web shells are then dropped into the PSEMHUB.war directory: x.jsp executes hex-encoded commands cross-platform, and u.jsp/u2.jsp upload larger files in 150 KB Base64-encoded chunks, bypassing PeopleSoft's own file-size limits; a fileless variant returns command output directly in the HTTP response with nothing written to disk, defeating file-creation-based detection. On compromised Windows hosts, the actor uploads a trojanized installer, Ple64.exe, masquerading as a signed Light Alloy media-player installer and signed with a valid Extended Validation certificate Mandiant has asked the issuing certificate authority to revoke; it loads a VMProtect-3-packed multi-stage chain culminating in the SIDEEYE C++ backdoor, which steals browser and desktop credentials, manages processes and files, and provides an interactive reverse shell and reverse proxy over raw TCP. The actor also deploys the open-source Neo-reGeorg tunneling toolkit to route SOCKS5 proxy traffic over ordinary HTTP/S for internal lateral movement, and uses the legitimate MeshAgent/MeshCentral remote-management platform to maintain access on Linux hosts. "Across compromised instances, a quarter of the threat actor's commands executed as root or NT Authority\SYSTEM, granting full control of the operating system" (Mandiant/GTIG, 2026-09-25).

Targeting has expanded well beyond the original higher-education skew: "Google says the new wave of attacks has deployed web shells on dozens of systems worldwide within higher education, technology, IT services, healthcare, agriculture, transportation, and government organizations" (BleepingComputer, 2026-09-26), and Mandiant's report names government among the sectors this wave has hit alongside the Council of Europe's earlier confirmed intergovernmental role. Mandiant's remediation guidance is unchanged in substance but sharper: apply the Oracle Security Alert and stay on a supported PeopleTools release rather than relying on a WAF at all; disable EMHub or remove PSEMHUB if not needed, since neither is required for standard PeopleSoft Internet Architecture user sessions; search WebLogic access logs for requests to /PSEMHUB/ and its encoded variants and for POST requests to /hub with external-source bodies; and, on any host where a web shell is found, treat it as compromised, preserve evidence, and rotate every credential reachable from the PeopleSoft tier, prioritising hosts where WebLogic runs as root or SYSTEM.

This wave also clarifies part of a separately-tracked claim: ShinyHunters told BleepingComputer it used this same WAF-bypass technique against the FBI's own recruitment site, alongside a further, still-unconfirmed vulnerability it says it also exploited there; see the FBI PeopleSoft entry for that update.