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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 · 5d agoMalware in the wild 3 sourcesCVE-2025-53521

Hackers Chain Chrome and Windows Zero-Days in New BlueMoon Exploit Kit Attacks

Multiple espionage actors, mostly China-nexus, are chaining Chrome V8 and Windows kernel zero-days (CVE-2026-85046, CVE-2026-85880) via the BlueMoon exploit kit against government and defense targets.

Proofpoint identified a new exploit kit dubbed BlueMoon chaining a Chromium V8 type-confusion RCE (CVE-2026-85046), a V8 sandbox escape, and a Windows kernel LPE (CVE-2026-85880). At least four distinct threat clusters, most with suspected China nexus, adopted the kit within days starting with TA412 (Violet Typhoon/APT31) on August 28, 2026. Both Chrome-side flaws were patch-gap zero-days with roughly a four-week exploitation window; the Windows LPE only works on Windows 10 and Server 2019/2022. TA412 used spearphishing posing as university interns to deliver the GemStone browser backdoor disguised as a Google Gemini extension; other clusters delivered ShadowPad via DLL sideloading and a Rust loader against targets in aerospace, government, and finance.

Cyber Security Newsupdated · 22h agofirst · 6d agoExploit / PoC in the wild 20 sourcesCVE-2026-85046CVE-2026-858801

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 · 27d agoThreat actor in the wildCVE-2026-12569

Acronis Plugin Vulnerability in cPanel and Plesk Exploited in the Wildnew

Acronis patched CVE-2026-87886 (CVSS 7.8), a local privilege escalation flaw in its cPanel and Plesk backup plugins, exploited in targeted attacks.

Acronis released fixes for CVE-2026-87886 (CVSS 7.8, CWE-276), an insecure file permissions flaw in Linux-based backup components for cPanel & WHM and Plesk that enables local privilege escalation. The vendor observed limited, targeted exploitation in the wild before patches shipped. Fixes are available in Backup plugin for cPanel & WHM 1.9.3 HF3 and Backup extension for Plesk 1.8.11. A local attacker with low privileges could gain elevated access to backup data, control panels, and other customer accounts on shared hosting infrastructure.

[0day-rubbish] core-admin 1.0.164 (build 16468) Systemic shell command injection via ineffective quote escaping (8.8)

0day Rubbish discloses a CVSS 8.8 shell command injection in core-admin 1.0.164 via ineffective quote escaping, enabling authenticated remote code execution.

0day Rubbish Research Team publicly disclosed a systemic shell command injection (CWE-78) in core-admin 1.0.164 (build 16468). The flaw stems from ineffective quote escaping and scores 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H). The disclosure does not mention a CVE identifier or observed exploitation in the wild.

Full Disclosure · 7d agoVulnerability1

PEEP: A Browser RAT Posing as a Chrome Extension

SOCRadar's STRU analyzed PEEP, an emerging Chromium-based RAT disguised as a Chrome extension enabling post-exploitation control of browsers.

SOCRadar's Threat Research Unit (STRU) identified and analyzed PEEP, a Chromium-based post-exploitation toolkit distributed as a browser extension. PEEP provides RAT-style capabilities while posing as a legitimate Chrome extension. It is assessed as an emerging threat worth monitoring by defenders.

SOCRadar · 11d agoMalware

Stack buffer overflow in WAD

FortiOS explicit proxy WAD daemon stack buffer overflow (CVSS 5.1) allows code execution only with Kerberos and SOCKS configured.

Fortinet advisory FG-IR-26-161 describes a stack-based buffer overflow (CWE-121) in the WAD daemon of FortiOS explicit proxy, scored CVSSv3 5.1. Exploitation requires an attacker able to bypass stack protection and ASLR, and the explicit proxy must be configured with Kerberos authentication and SOCKS enabled. If successful, it yields arbitrary code or command execution in the WAD daemon context via crafted sockets. No exploitation is reported in the advisory.

Fortinet PSIRT · Aug 12, 2026Advisory

Redtail Payload Analysis [Guest Diary], (Wed, Sep 9th)

SANS guest analyst detonated a RedTail Linux sample from a DShield honeypot, finding process masquerading as php-fpm, monitoring-kill behavior, and a TCP listener.

A DShield honeypot captured multi-architecture RedTail Linux executables (ARM, ARM64, i686, RISC-V, x86-64) deployed via shell scripts. Dynamic analysis of the UPX-packed, statically linked x86-64 sample (SHA-256 63be5f38...d35e) in an isolated Ubuntu 24.04 VM on Proxmox showed it renamed its process via prctl(PR_SET_NAME), killed a filesystem-monitoring process, and opened a TCP listening socket while surviving processes posed as php-fpm or PostgreSQL-like workers. Differential memory images pre- and post-execution were captured from the hypervisor for forensics.

SANS Internet Storm Center · 5d agoMalware in the wild 2 sources1

PEEP Turns Chrome and Edge Into Post-Compromise Backdoors for Host Command Execution

SOCRadar disclosed PEEP, a post-exploitation Chromium extension toolkit that turns Chrome and Edge into host-level backdoors via native messaging and C2 polling.

SOCRadar researchers detailed PEEP, a Chromium-based post-exploitation toolkit masquerading as a 'Smart Bookmarks' extension injected directly into Chrome and Edge profiles by forging Secure Preferences integrity values, bypassing Web Store checks. A native-messaging host binary (nm_host.exe) extends the browser agent to host-level command execution, file management, credential theft, and session hijacking, while the extension polls C2 endpoints at 206.237.30.232 or xfjcc.fun every 30 seconds over plaintext HTTP and exfiltrates browsing history, cookies, and tab metadata. PEEP is derived from the open-source RedExt red teaming framework, adds PowerShell persistence scripts, and includes a Linux-targeting Python script, suggesting cross-platform intent. The activity is unattributed but contains Chinese-language artifacts; a C2 /health endpoint showed 34 agent entries and 10 active sessions.

The Hacker News · 8d agoMalware in the wild

terms.txt: A Consent and Compensation Protocol for Agentic Web Access

terms.txt specifies a robots.txt-style protocol for per-path, per-purpose AI crawler consent and compensation, with enforcement adding 0.20-0.65 ms per request.

The paper documents that automated clients now make up most web requests, that training dominates Cloudflare-classified crawling, and that the largest AI platforms fetch thousands of pages per returned visitor while robots.txt cannot express identity, purpose, terms, or price. It specifies terms.txt plus an origin-enforced exchange using Web Bot Auth signatures, signed intent, delegation tokens, HTTP 402 negotiation, and signed receipts. A dependency-free implementation adds 0.20 to 0.65 ms per request on one vCPU.

arXiv cs.CR · 6d agoResearch

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

ZDI-26-587: Ashlar-Vellum Cobalt VS File Parsing Heap-based Buffer Overflow Remote Code Execution Vulnerability

ZDI advisory ZDI-26-587 details a heap-based buffer overflow RCE (CVE-2026-19781, CVSS 7.8) in Ashlar-Vellum Cobalt VS file parsing, requiring user interaction.

The Zero Day Initiative released advisory ZDI-26-587 covering a heap-based buffer overflow in Ashlar-Vellum Cobalt's VS file parsing. A remote attacker can execute arbitrary code when the target opens a malicious file or visits a crafted page. ZDI rated the vulnerability CVSS 7.8 and assigned CVE-2026-19781.

ZDI-26-590: libwebsockets HTTP/2 HPACK Path Header Parsing Out-Of-Bounds Write Remote Code Execution Vulnerability

ZDI disclosed CVE-2026-19773, an unauthenticated out-of-bounds write allowing remote code execution in libwebsockets HTTP/2 HPACK parsing, rated CVSS 9.8.

The Zero Day Initiative published advisory ZDI-26-590 for an out-of-bounds write vulnerability in libwebsockets' HTTP/2 HPACK path header parsing. A remote attacker can execute arbitrary code on affected installations without authentication. The flaw is tracked as CVE-2026-19773 and carries a CVSS score of 9.8.

Linux Detection Engineering - Local Privilege Escalation

Elastic details a layered detection framework for Linux local privilege escalation, covering 2026's copy-on-write bug wave and LLM-assisted discovery.

Elastic Security Labs describes how most Linux local privilege escalations share a common host flow — an unprivileged process launched from a writable path becoming root — and proposes layered detections combining general outcome-based rules with per-technique rules in Elastic Defend and Auditd. It tracks 13 recent LPE disclosures, seven of which share a copy-on-write/zero-copy bug class, including Copy Fail, DirtyFrag, Fragnesia, DirtyDecrypt, DirtyClone, pedit COW, and RefluXFS. Qualys attributes RefluXFS to an LLM-assisted research effort with Anthropic using Claude Mythos Preview, and another bug is credited to an LLM-assisted workflow. Detection and endpoint rules are published in Elastic's detection-rules and protections-artifacts repositories.

Elastic Security Labs · 5d agoResearch

ZDI-26-636: Oracle Outside In Technology PostScript File Parsing Heap-based Buffer Overflow Remote Code Execution Vulnerability

ZDI disclosed a heap-based buffer overflow in Oracle Outside In Technology's PostScript parsing (CVE-2026-60412) enabling user-triggered remote code execution.

Zero Day Initiative published ZDI-26-636, a CVSS 7.8 heap-based buffer overflow in PostScript file parsing within Oracle Outside In Technology. Remote attackers can execute arbitrary code when the target opens a malicious file or visits a malicious page, making user interaction a requirement. The vulnerability is tracked as CVE-2026-60412. The advisory reports no exploitation.

New Ted Backdoor Hides Inside Victims' Own HAProxy Builds to Intercept Web Traffic

Rapid7 found a new backdoor, ted, compiled into trojanized HAProxy at two South Korean organizations, with medium-confidence attribution to North Korean actors.

Rapid7 documented a previously undocumented Linux toolkit named ted compiled into the HAProxy load balancer binaries of two South Korean organizations in the automotive and media sectors. The implant intercepts web traffic, serves altered pages only to filtered visitors, and hides C2 exchanges from backend logs and HAProxy statistics; a companion RAT, curlRAT, beacons on a default 12-hour schedule. The toolkit also trojanizes crond, sshd, agetty, atd, and polkitd binaries and sanitizes logs and bash history. Rapid7 attributes the activity with medium confidence to North Korean state-sponsored actors, with domain infrastructure overlapping APT37 listings in maltrail and delivery resembling the Operation SyncHole campaign.

The Hacker News · 11d agoThreat actor in the wild

Trends in Web Threats in CY Q2 2022: Malicious JavaScript Downloaders Are Evolving

Unit 42 detected 751,000 landing URL incidents in Q2 2022 and documented malicious JavaScript downloaders evolving to evade detection.

Unit 42 detected 751,331 landing URL incidents (253,644 unique) and 1,744,629 malicious host URL incidents (256,844 unique) from April through June 2022. Total landing URL incidents rose compared with Q1 2022, and unique host URL incidents grew 42%, indicating attackers deploying more variants. The report includes a case study of a JavaScript downloader campaign demonstrating new evasion techniques. Personal sites, blogs, and business sites were the top apparently benign entry points.

Palo Alto Unit 42 · 29d agoResearch

DPRK APTs: Ted backdoor and curlRAT target South Korean media and automotive sectors

Rapid7 uncovered a DPRK-linked Linux toolkit using a HAProxy-embedded ted backdoor, SSH keylogger, and curlRAT against South Korean media and automotive firms.

Rapid7 Labs identified a previously undocumented framework attributed with medium confidence to DPRK actors, targeting South Korean automotive and media organizations likely since early 2025. The toolkit embeds a backdoor compiled into HAProxy 2.8.12 using its filter API, plus trojanized crond, agetty, atd, sshd, and polkitd, an SSH keylogger storing credentials under /var/lib/sshd/, and a curl-based RAT with a watchdog thread. It enables remote command execution, malicious script injection into served webpages (a watering-hole loop), credential harvesting, and long-term surveillance. Hardcoded C2s are associated with APT37 via ThreatFox, and exposed groupware portals and mail servers align with Kimsuky tradecraft; the initial access vector and any CVE remain unconfirmed.

Rapid7 Blog · 11d agoThreat actor in the wild1

Bulk AbuseIPDB reporting using command-line tools

A blogger shows how to bulk-report distributed botnet IPs scraping a self-hosted Gitea instance to AbuseIPDB using bash, awk, and jq.

The author's self-hosted Gitea instance was scraped by distributed bots using random IPs worldwide and randomized, often nonexistent User-Agent strings, generating heavy request load for days. The write-up demonstrates filtering Traefik access logs (CLF and JSON) with grep, awk, and jq to extract offending IPs, tagging them with AbuseIPDB category 19 (Bad Web Bot), deduplicating them, and building a CSV for the Bulk Reporter tool. Reports can then be submitted through the AbuseIPDB bulk-report API, respecting the 5,000-report daily limit.

Lobsters · security · 6d agoTools1

Researchers Use Claude to Port Pre-Auth RCE Exploit From One PLC Model to Another

Forescout used Anthropic's Claude to port a working pre-auth RCE exploit for CVE-2021-31886 between WAGO PLCs, executing ARM shellcode on live hardware.

Forescout Vedere Labs used Claude interactively to port an RCE exploit for CVE-2021-31886, a CVSS 9.8 stack buffer overflow in the Nucleus FTP server's USER command, from a WAGO 750-852 to a WAGO 750-831 PLC, running attacker-supplied ARM shellcode. The final RCE stage cost $535.74 in API usage over 8 hours 32 minutes, and a follow-up attempt to build a C2 implant permanently bricked the device. CERT@VDE lists many Nucleus V1-based WAGO models as vulnerable with no updates available; Siemens plans no Nucleus NET remediation. The work follows a joint NSA/CISA/FBI/DOE/EPA advisory warning of AI-generated exploitation scripts targeting internet-exposed Siemens S7 PLCs.

The Hacker News · 14d agoResearchCVE-2021-318862

Trends in Web Threats: Old Web Skimmer Still Active Today

Unit 42 detected 577,000 landing URL incidents in Q1 2022, with an old web skimmer family still actively stealing payment card data.

Palo Alto Unit 42 detected 577,275 landing URL incidents (116,643 unique) and 2,043,862 malicious host URL incidents (180,370 unique) between January and March 2022. Web threat volumes declined after the November 2021 holiday peak, but an old web skimmer family remained active. Business and economy sites overtook personal sites as the most common apparently benign entry points. Most malicious domains geolocated to the United States, Germany, and Russia, though proxy servers and VPNs obscure true locations.

Palo Alto Unit 42 · 29d agoResearch

Human Attacker Hits Machine-Speed Exploitation of Marimo RCE

Sysdig details a human attacker chaining pre-auth RCE in Marimo (CVE-2026-39987) to AWS credentials and a bastion host in eight seconds.

Sysdig's Threat Research Team documented an intrusion where an operator exploited CVE-2026-39987, a pre-auth RCE in the Marimo notebook terminal WebSocket endpoint, gaining an interactive shell with no credentials. The attacker harvested AWS credentials from the process environment and Redis backend, retrieved an SSH private key from AWS Secrets Manager, and authenticated to an internet-reachable bastion host. The chain fired in eight seconds after roughly four hours of toolkit building, logging over 850 commands during a nine-hour session. The flaw, fixed in Marimo 0.23.0, has been on CISA's KEV catalog with a May 7, 2026 federal remediation deadline.

Infosecurity Magazineupdated · 20h agofirst · 1d agoExploit / PoC in the wild 4 sourcesCVE-2026-39987

Metasploit Wrap Up: Lot of summer shells and fit http profiles

Metasploit 6.5 ships 13 new modules including RCEs for SonicWall SMA1000, Ghost CMS, Joomla JCE and Langflow, plus a Linux kernel LPE.

Rapid7's Metasploit wrap-up covers the 6.5 release, which adds 13 new modules, including remote code execution exploits for WordPress WP2Shell, Ghost CMS, Joomla JCE, Langflow, OpenCATS, Pterodactyl Panel, SonicWall SMA1000, Ray Dashboard and a Pix-for-WooCommerce plugin. The Fragnesia Linux kernel local privilege escalation (CVE-2026-46300) also landed. The release introduces HTTP malleable profiles, MCP functionality, Linux multi-fetch payloads and improved Windows on ARM support.

Rapid7 Blog · Aug 14, 2026ToolsCVE-2026-46300

CVE-2026-87464: RCE outside sandbox in Chromium prior to 153.0.8010.36

CVE-2026-87464 is a critical use-after-free in Chrome's WebGL allowing sandbox-escaping RCE via crafted HTML pages, fixed in 153.0.8010.36.

Google Chrome prior to 153.0.8010.36 contains a use-after-free in WebGL that allows a remote attacker to execute arbitrary code outside the sandbox via a crafted HTML page. Google rates it as Chromium security severity Critical, though tracker details are restricted. Debian indicates all current Chromium packages are affected, and the flaw likely impacts Chromium-derived browsers. No active exploitation is mentioned in the disclosure.

oss-security · 5d agoVulnerabilityCVE-2026-87464

Chrome V8 Zero-Day Exploited in the Wild Enables Code Execution Inside Sandbox

Google patches actively exploited Chrome V8 zero-day CVE-2026-87491, an out-of-bounds write enabling sandboxed code execution via crafted HTML pages.

Google released Chrome 153.0.8010.36/.37 fixing 230 vulnerabilities, including CVE-2026-87491, an out-of-bounds write in the V8 engine that allowed remote code execution inside the sandbox via a crafted HTML page and is confirmed to be exploited in the wild. The flaw was reported on August 6, 2026 by Jihyeon Jeong of Compsec Lab, Seoul National University, who received a $2,500 bug bounty. This is the seventh actively exploited Chrome zero-day of 2026. The update also fixes five critical flaws in WebGL and Cast, plus a high WebPackaging use-after-free (CVE-2026-87639) credited to OpenAI Codex Security.

The Hacker News · 6d agoExploit / PoC in the wildCVE-2026-87491CVE-2026-2441CVE-2026-3909+10 CVEs

Linux Detection Engineering - Fileless Execution

Elastic Security Labs reproduces five Linux fileless execution patterns, including memfd_create staging and in-memory kernel module loads, and maps each to Elastic Defend rules.

Elastic Security Labs reproduced five Linux fileless execution patterns using its FENIX tooling: memfd_create staging, interpreter one-liners, deleted binaries, and in-memory kernel module loads. Each pattern is mapped to the Elastic Defend detection rules that catch it. The post is part of the team's ongoing Linux detection engineering series.

Elastic Security Labs · 14d agoResearch

Google fixes the sixth actively exploited Chrome zero

Google patched 12 Chrome flaws including actively exploited V8 type confusion zero-day CVE-2026-85046 (CVSS 8.8), enabling sandboxed remote code execution via crafted webpages.

Google released Chrome Stable 152.0.7977.82/.83 for Windows and Mac and 152.0.7977.82 for Linux, fixing 12 vulnerabilities including CVE-2026-85046, a type confusion in V8 with a CVSS score of 8.8. Google says an exploit exists in the wild, making this the sixth actively exploited Chrome zero-day of 2026. The bug affects the JavaScript and WebAssembly engine and allows arbitrary code execution inside the browser sandbox via a specially crafted HTML page. Researcher Salvatore Gulizia (Serotav) reported the flaw on August 4, 2026 and received a $1,000 bounty.

Security Affairs · 11d agoExploit / PoC in the wildCVE-2026-85046CVE-2026-2441CVE-2026-3909+3 CVEs1

Version Control DFIR: a Cheatsheet to GitHub, GitLab, Bitbucket, and Azure DevOps

Wiz published a DFIR cheatsheet covering log visibility, incident readiness, and threat hunting across GitHub, GitLab, Bitbucket, and Azure DevOps.

Wiz researchers released a practitioner's guide to version control system forensics, incident response, and threat hunting. The cheatsheet maps log sources, audit capabilities, and hunting workflows across GitHub, GitLab, Bitbucket, and Azure DevOps. It aims to improve incident readiness for source code and CI/CD compromise scenarios.

Wiz Blog · 19d agoResearch1