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Clop-Linked Windchill Web Shell Decrypts Credentials and Maps Engineering Data

ReliaQuest details a bespoke JSP web shell that Clop deploys on hacked PTC Windchill and FlexPLM servers after exploiting CVE-2026-12569.

ReliaQuest analyzed a custom Java web shell planted on vulnerable PTC Windchill and FlexPLM servers following exploitation of CVE-2026-12569 (CVSS 9.3). The implant decrypts Windchill keystore credentials including the LDAP manager password, enumerates the file vault for engineering data, and loads attacker-supplied Java classes in memory for post-exploitation. Commands let operators read and delete files, exfiltrate results, and deliver follow-on payloads such as ransomware. Ransom-ISAC, eCrime.ch and Defused previously attributed the campaign to the Clop data-theft extortion group.

The Hacker News · 28d agoThreat actor in the wildCVE-2026-12569

Hackers deploy Linux rootkit on F5 BIG-IP APM devices, hiding web shell in memory

Sophos analyzed a Linux rootkit, tracked as PoisonedRefresh, on hacked F5 BIG-IP APM devices hiding an in-memory web shell linked to exploited CVE-2025-53521.

Sophos and ESET analyzed an implant (named PoisonedRefresh by ESET) deployed on compromised F5 BIG-IP APM appliances, which serves enterprise, financial, government, and public sector deployments. The second-stage payload intercepts __libc_start_main, hooks Apache's APR module loader (apr_dso_load), RC4-encodes key strings, and rewrites PHP file reads in memory to embed a web shell inside legitimate scripts like apm_css.php3, full_wt.php3, and webtop_popup_css.php3, leaving on-disk files unchanged. A related installer component infects /usr/sbin/httpd, persists across BIG-IP upgrade images, modifies SELinux configuration, and deploys the payload. The malware also creates a Unix domain socket at /run/bigtlog.pipe that hands authenticated local connections to /bin/bash; F5 links the activity to CVE-2025-53521, an unauthenticated RCE in BIG-IP APM already exploited in the wild.

Help Net Security · 7d agoMalware in the wildCVE-2025-535211

F5 BIG-IP APM Malware Injects a PHP Web Shell Into Memory, Evading Disk Scans

Sophos found F5 BIG-IP APM malware that injects a PHP web shell into Apache's memory, evading disk scans, linked to exploited CVE-2025-53521.

Sophos's September 7 analysis describes malware tied to F5's c05d5254 activity that hooks apr_dso_load, modifies the libphp PHP module in memory, and injects a PHP web shell when Apache loads apm_css.php3, full_wt.php3 or webtop_popup_css.php3, leaving on-disk files clean. A separate installer infects /usr/sbin/httpd and umount, runs before Apache starts, disables SELinux (per ESET's related PoisonedRefresh analysis), and opens a local socket at /run/bigtlog.pipe for shell access. The activity is linked to CVE-2025-53521 in BIG-IP APM, rated 9.8 CVSS 3.1, patched in October 2025, added to CISA KEV on March 27, 2026.

The Hacker News · 7d agoMalware in the wildCVE-2025-53521

PoisonedRefresh: A Fileless Linux Rootkit That Injects PHP Web Shells Into F5 BIG-IP APM Server Memory

Sophos details PoisonedRefresh, a fileless Linux rootkit that injects a memory-resident PHP web shell into F5 BIG-IP APM after exploitation of CVE-2025-53521.

On September 8, 2026, SophosLabs published an analysis of Linux/Agnt-IC (dubbed PoisonedRefresh by ESET) found in compromised F5 BIG-IP Access Policy Manager environments. Initial access leverages CVE-2025-53521, an unauthenticated RCE in BIG-IP APM when an access policy is configured on a virtual server; F5 confirmed exploitation and links the activity to cluster c05d5254, while Shadowserver observed 795 exposed vulnerable endpoints. A first stage hidden in a modified umount binary modifies /usr/sbin/httpd and SELinux configuration and embeds itself in BIG-IP upgrade images for persistence. The second-stage ELF intercepts __libc_start_main, hooks apr_dso_load, and injects a PHP web shell into libphp memory via mmap manipulation, leaving no disk artifacts, and exposes a /bin/bash shell via a local UNIX domain socket instead of a TCP port.

Security Affairs · 7d agoMalware in the wildCVE-2025-53521

Persistent Attempts at Cyberespionage Against Southeast Asian Government Target Have Links to Alloy Taurus

Alloy Taurus (GALLIUM) compromised Southeast Asian government networks from 2022 to 2023 using Exchange web shells and undocumented .NET backdoors Reshell and Zapoa.

Unit 42 tracked persistent multiwave intrusions at a Southeast Asian government starting in early 2022 and continuing through 2023, attributing the activity with moderate confidence to Alloy Taurus (aka GALLIUM), a Chinese state-aligned espionage group. Attackers exploited Exchange Server vulnerabilities to deploy web shells including China Chopper, then ran reconnaissance with Fscan and WebScan, created administrative accounts, and installed undocumented .NET backdoors named Reshell and Zapoa. They established resilience by installing SoftEther VPN, brute-forced Active Directory credentials with Kerbrute, and dumped credential stores with GoDumpLsass and LsassUnhooker. The campaign reflects long-term espionage tradecraft to maintain a foothold.

Palo Alto Unit 42 · Aug 17, 2026Threat actor in the wild1

CISA Adds Seven Exploited Flaws as Attackers Deploy Reverse Shells and Crypto Miners

CISA added seven actively exploited vulnerabilities to its KEV catalog, including SonicWall SMA 1000 SSRF CVE-2026-83548, amid campaigns deploying reverse shells and crypto miners.

CISA's KEV additions cover flaws in SonicWall SMA 1000 (CVE-2026-83548, CVE-2026-83549), Sangoma Switchvox (CVE-2026-9586), JFrog Artifactory (CVE-2026-82329), Kludex Starlette (CVE-2026-48710), Kestra OSS (CVE-2026-49869) and Berri LiteLLM's MCP endpoint (CVE-2026-59822). SonicWall confirmed active exploitation of the SMA 1000 flaws, while Microsoft and Wiz reported attackers chaining LiteLLM flaws CVE-2026-42271 and CVE-2026-48710 to fingerprint hosts, steal provider API keys and deploy XMRig miners on AI infrastructure. Wiz linked exploitation of the LiteLLM chain to the Qilin ransomware group, and Microsoft detailed a Kestra compromise chain ending in cryptocurrency mining and data harvesting via exposed RAGFlow flaws.

The Hacker News · 13d agoExploit / PoC in the wildCVE-2026-83548CVE-2026-83549CVE-2026-9586+10 CVEs1

Active exploitation of Cisco Secure Firewall Management Center vulnerabilities

Cisco Talos reports in-the-wild exploitation of critical FMC flaw CVE-2026-20079 by three clusters including a Sandworm-linked APT and Qilin ransomware affiliates.

Cisco Talos is tracking active exploitation of CVE-2026-20079 (CVSS 10.0), an authentication bypass in Cisco Secure Firewall Management Center that lets unauthenticated remote attackers execute scripts and obtain root access, and CVE-2026-20316 (CVSS 5.3), which permits low-privileged logins and can be chained for privilege escalation. Talos identified three post-compromise clusters: UAT-12197 deploying JSP web shells and a JAR command executor for credential theft; UAT-11823, an APT overlapping with Sandworm, deploying a Netcat reverse shell and Cyclops Blink malware; and UAT-11988, assessed as a ransomware operator with TTPs consistent with Qilin affiliates. Hotfixes are available, with a comprehensive hardening release due the week of September 14, 2026.

Cisco Talos · 7d agoExploit / PoC in the wild 2 sourcesCVE-2026-20079CVE-2026-20316

Cl0p Targets 40+ Organizations Through PTC Windchill Flaw

Cl0p claims over 40 organizations including Shell and Philips were breached by exploiting critical RCE CVE-2026-12569 in PTC Windchill and FlexPLM.

Cl0p claims more than 40 organizations were victimized via CVE-2026-12569 (CVSS 9.3), a critical deserialization-based remote code execution flaw in PTC Windchill PDMlink and FlexPLM, affecting releases prior to 11.0 M030; CISA added the flaw to its KEV catalog in June. ReliaQuest found the group deployed a custom web shell that maps vault data, decrypts all credentials in the Windchill keystore, and includes a Java class loader enabling arbitrary code execution, lateral movement, persistence, and large-scale data exfiltration without extra tooling. Named victims include Shell, Philips, Fiserv, Zebra Technologies, Ingersoll Rand, Toast, Mindray, and Apple lens supplier Largan Precision, with stolen data ranging from one gigabyte to multiple terabytes per target. The campaign mirrors Cl0p's earlier mass-exploitation extortion operations against MOVEit, Cleo, GoAnywhere, and Oracle E-Business Suite.

Security Affairs · 26d agoRansomware in the wildCVE-2026-12569

Stealth rootkit targeting F5 BIG-IP could expose enterprise identity gateways

Sophos analyzed a stealth Linux rootkit that hides a web shell in memory on compromised F5 BIG-IP APM identity gateways, evading file-based detection.

Sophos analyzed a second-stage Linux rootkit implant found in compromised F5 BIG-IP APM environments running Apache and PHP, linked to exploitation of CVE-2025-53521, an unauthenticated RCE. The implant hooks Apache's PHP-loading process and serves modified in-memory versions of three legitimate webtop PHP files (apm_css.php3, full_wt.php3, webtop_popup_css.php3), leaving on-disk files untouched so hashes and integrity checks pass. It also establishes access via an authenticated local UNIX socket that can provide an interactive /bin/bash session. Experts warn compromised APM appliances, which handle federated SSO and terminate TLS at enterprise perimeters, could enable SSO token theft and lateral movement to trusted downstream applications.

CSO Online · 6d agoMalware in the wildCVE-2025-53521

Keys to the Kingdom: Erlang/OTP SSH Vulnerability Analysis and Exploits Observed in the Wild

Attackers actively exploit CVE-2025-32433, a CVSS 10.0 unauthenticated RCE in Erlang/OTP SSH, heavily targeting OT and critical infrastructure networks.

CVE-2025-32433 enables unauthenticated RCE in Erlang/OTP's SSH daemon via SSH connection protocol messages (codes >= 80) processed before authentication, affecting versions before OTP-27.3.3, OTP-26.2.5.11 and OTP-25.3.2.20. Unit 42 recorded a spike in exploitation between May 1-9, 2025, with 70% of detections on firewalls protecting OT networks, disproportionately affecting healthcare, agriculture, media and high technology. Observed payloads bind TCP-connected shells or launch Bash reverse shells to hosts like 146.103.40.203:6667, with randomized DNS lookups under dns.outbound.watchtowr.com indicating OAST-driven blind RCE validation.

Palo Alto Unit 42 · Aug 17, 2026Exploit / PoC in the wildCVE-2025-32433

Attackers Exploit Critical Switchvox Flaw to Deploy Reverse Shells Without Credentials

Attackers exploit unauthenticated SQL injection CVE-2026-9586 in Sangoma Switchvox to run PostgreSQL commands and deploy reverse shells.

Threat actors are exploiting CVE-2026-9586 (CVSS 9.3), an unauthenticated SQL injection in Sangoma Switchvox SMB Edition 8.3 (104997), since August 30, 2026, running arbitrary SQL as the PostgreSQL superuser and achieving remote code execution. The /pa endpoint concatenates the user-controlled PhoneIP value into PostgreSQL queries; attackers can extract database contents, escalate to Switchvox web administrator, exfiltrate the cookie signing key to forge authentication, and invoke reverse shells. Sangoma patched the flaw in Switchvox 8.4.0.2 on July 14, 2026, roughly 4,000 instances are internet-exposed (mostly in the US), and honeypot activity from IP 176.65.148.184 deploys reverse shells followed by Base64-encoded process enumeration.

The Hacker News · 14d agoExploit / PoC in the wildCVE-2026-9586

Attackers Exploit WooCommerce Wholesale Lead Capture Flaw to Plant PHP Web Shells

Attackers exploit CVE-2026-27540 in WooCommerce Wholesale Lead Capture to upload PHP web shells; Wordfence blocked 100,000+ attempts since June 2026.

Wordfence reports active exploitation of CVE-2026-27540 (CVSS 9.8), an unauthenticated arbitrary file upload in the wwlc_file_upload_handler AJAX action of the WooCommerce Wholesale Lead Capture plugin (versions through 2.0.3.1, 6,000+ installs), enabling remote code execution via uploaded PHP web shells. Over 100,000 exploit attempts were blocked since June 2026, including 99 in the last 24 hours, traced to ten listed IP addresses. Separately, two critical flaws (CVE-2026-78159 and CVE-2026-78006) in The Events Calendar, installed on 600,000+ sites, allow unauthenticated RCE and full site takeover via PHP object injection chains. StellarWP patched the affected plugin versions 6.17.3 and 6.17.4 in releases 6.17.3.1 and 6.17.4.1.

The Hacker Newsupdated · 5h agofirst · 14h agoExploit / PoC in the wild 6 sourcesCVE-2026-27540CVE-2026-78159CVE-2026-78006

Hackers Exploit FortiGate SSL-VPN Flaw to Breach Thai ISP and Deploy MeshCentral Backdoor

Threat actors exploited FortiOS SSL-VPN flaw CVE-2024-21762 to breach Thai ISP Triple T Broadband, gaining root-level persistence via MeshCentral agents.

Attackers exploited CVE-2024-21762, an out-of-bounds write enabling unauthenticated RCE in FortiOS SSL-VPN, against Triple T Broadband's FortiGate 60F at mail.3bb.co.th, launching a Node.js reverse shell via a ROP payload. Hunt.io uncovered the operation through an exposed staging directory at 92.63.180[.]133:8888 containing 298 files of exploits, credential-harvesting scripts, session cookies, and a device inventory. Post-compromise, the actors deployed MeshCentral agents (device group TH-3BB, C2 www.ayuthayatech.com) running as root, plus a hidden SUID backdoor at /usr/local/bin/.rc, and also targeted an internal Pentaho/Tomcat server with Ghostcat (CVE-2020-1938). A cleanup script removed logs, shell histories, and web shells while deliberately preserving the MeshCentral agent and SUID backdoor.

GBHackers · 1d agoExploit / PoC in the wild 3 sourcesCVE-2024-21762CVE-2020-1938

Adobe Patches Magento Zero-Day Exploited to Deploy Rust Backdoor and PHP Web Shell

Adobe patches actively exploited Magento zero-day CVE-2026-75650 (CVSS 10.0), abused since Sept 4 to deploy a Rust backdoor and PHP web shells.

Adobe released an emergency hotfix (VULN-39341) for CVE-2026-75650 (CVSS 10.0), dubbed StyleSmuggler by Sansec, which abuses Magento's template system via PHP code injection to trigger unauthenticated remote code execution in Adobe Commerce and Magento Open Source. Exploitation began September 4, 2026, with attackers deploying a Rust-based Linux backdoor and a PHP dropper that writes a web shell; one managed server was compromised 50 minutes after the first report. Previdian honeypots recorded 12 exploitation attempts from two unique IPs in China and Romania since September 7, all unsuccessful. Adobe urges merchants to apply the patch and rotate encryption keys.

The Hacker News · 8d agoExploit / PoC in the wildCVE-2026-75650