Introduction
Mandiant and Google Threat Intelligence Group (GTIG) have identified an active compromise and extortion campaign attributed to UNC6240 (ShinyHunters) targeting Oracle PeopleSoft application infrastructure. The activity was observed between May 27, 2026, and June 9, 2026 and is consistent with the exploitation of CVE-2026-35273, a critical remote code execution vulnerability (CVSS 9.8) in the Environment Management component. The exploitation of this vulnerability directly aligns with the observed targeting of Environment Management Hub (PSEMHUB) endpoints. Because this activity predates Oracle’s June 10, 2026 advisory, the vulnerability was exploited as a zero-day.
Upon becoming aware of active scanning and exploitation, we initiated notifications to over 100 global organizations whose IP addresses correlated with potentially vulnerable endpoints. Most of these organizations were based in the United States, and 68 percent operated within the higher education sector. Subsequently, public reports by @nahamike01 on X highlighted open attacker directories on the staging servers, allowing GTIG to perform a detailed triage of the threat actor’s operations.
The attacker staging environments hosted customized MeshCentral agents masquerading as legitimate cloud endpoints, which they used to run administrative command queries and deploy a custom lateral movement and defacement script, [victim_abbreviation]_fanout.sh. This campaign directly correlates with subsequent data leaks of stolen organization data published on the ShinyHunters Data Leak Site (DLS) on June 9, 2026.
We recommend that organizations running Oracle PeopleSoft take the following immediate actions to best defend themselves. Additional remediation and hardening guidance is included later in this post.
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Threat Detail & Campaign Overview
On June 9 2026, public threat reports highlighted open attacker directories. GTIG triaged five sequential IP addresses: 142.11.200.186, 142.11.200.187, 142.11.200.188, 142.11.200.189, and 142.11.200.190. These systems were hosting Python SimpleHTTP servers on port 8888, exposing directory contents that included staging materials, customized agents, and attacker command histories.
The staging infrastructure hosted pre-configured Windows MeshCentral agent binaries disguised as Microsoft Azure services, specifically named meshagent32-azure-ops.exe, meshagent64-azure-ops.exe, and meshagent64-v2.exe. MeshCentral is an open-source remote management server; its agent is software that runs on remote devices to allow for remote management across various operating systems, including Windows, Linux, macOS, and FreeBSD. Static analysis indicates these agents were hardcoded to establish communication with the command and control (C2) server
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