Search: “OSS-Fuzz”

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Sandworm-Linked Cyclops Blink Returns With Network Scanning and Packet-Sniffing Capabilities

Sophos uncovers a 64-bit Cyclops Blink variant on hacked Cisco FMC appliances, adding internal network scanning and selective packet capture; linked to Sandworm.

Sophos CTU analyzed a new 64-bit x86-64 Cyclops Blink implant (timezone_check) deployed on Cisco Secure Firewall Management Center appliances compromised via CVE-2026-20079 authentication bypass and CVE-2026-20316 low-privileged login. The activity is assessed with high confidence as Russian-nexus, with a moderate-confidence link to Sandworm (IRON VIKING, also tracked as Seashell Blizzard). The implant runs a parent controller plus five worker modules, masquerades as [kworker/0:1], persists via SysV init scripts at /lib/tz/timezone_check, and beacons to hard-coded C2 89.34.96.56 over a custom TLS protocol on ports 43856 and 49172. New module 0x11 scans internal IPv4 networks for SSH, SMB, LDAP, VMware, HTTP/HTTPS and VPN services, while module 0x12 performs filtered packet capture that can expose cleartext credentials, cookies and tokens.

GBHackers·Sep 14, 09:27 UTC · 2d agoMalware in the wild 9 sourcesCVE-2026-20079CVE-2026-20316

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Hackers Use ClickFix Lures to Deploy MacSync Stealer and Bypass macOS Security.

ClickFix malvertising campaigns deliver MacSync, a macOS infostealer sold as MaaS that bypasses Gatekeeper via Terminal commands and steals credentials.

Threat actors use ClickFix social-engineering lures, SEO poisoning, and malvertising impersonating brands like Claude, ChatGPT, Zoom, and Docker to trick users into pasting curl-to-zsh commands into Terminal, evading Gatekeeper and notarization checks. The MacSync Stealer (formerly Mac.c, emerged April 2025, linked to developer 'Mentalpositive') is a 64-bit Mach-O stager with single-byte XOR string obfuscation that daemonizes, polls C2 with custom API-key headers, streams AppleScript payloads into osascript, and persists via fake LaunchAgents. It steals browser credentials, Keychain data, SSH keys, session tokens, and crypto wallets, exfiltrating archives in 10MB HTTP PUT chunks. Microsoft documented more than 30 related MacSync domains.

GBHackers·updated Sep 10, 09:53 UTC · 6d ago·first Sep 10, 07:01 UTC · 6d agoMalware in the wild 2 sources

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Re: Retrospective by 'gpg.fail' authors

GPG exploitation talk author clarifies a format-string 0day enabling code execution via printf %n writes and a polyglot PEM certificate payload.

Lexi Groves, author of the gpg.fail talk, clarified on oss-security that the first finding was an actual zero-day: a classic printf injection using %n for memory writes, with multiple X.509 certificates in one PEM file to re-enter and defeat ASLR before calling execv@plt. The payload executed the certificate itself, a polyglot file made by inserting a shebang and bash command into the PEM. A second finding was hash-collided by another party before the author could exploit it.

oss-security·updated 17:16 UTC · 5h ago·first 00:50 UTC · 21h agoResearch 8 sources

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Russian State-Sponsored Hackers Use Claude to Rebuild Malware After Detection

Anthropic disrupted APT29-linked GTG-20006, which used Claude to autonomously rebuild malware, hijack hotel Wi-Fi DNS, and target 20-plus Ukrainian, European, and US-linked organizations.

Anthropic attributed the campaign to GTG-20006, aligned with Midnight Blizzard (APT29/Cozy Bear), which developed an AI-driven process that monitors its implants against security products and autonomously rebuilds and redeploys detected malware. Targets included military intelligence, diplomatic, and defense organizations in Ukraine and Europe, plus Middle East and Asian maritime agencies; the actor compromised at least three hotel Wi-Fi vendors via DNS hijacking and served ClickFix lures delivering Windows, Android, and iOS malware such as PowerChrome, GiftDrop, and DarkSword. Operations also included a North African breach exfiltrating over 300,000 national identity records and 500,000-plus company registry entries, an Embassy Kit device-code phishing campaign stealing Microsoft 365 tokens from at least eight organizations, and WhatsApp account takeover using headless browsers. The campaign overlaps with CaptiveCrunch reporting from ReliaQuest, Microsoft, Google, and Lumen Black Lotus Labs.

The Hacker News·updated 13:01 UTC · 9h ago·first Sep 11, 14:10 UTC · 5d agoThreat actor in the wild 18 sources2

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Code review used to be the only way to catch these bugs

Palo Alto Networks' Unit 42 says its NOVA system found 14,090 vulnerabilities in 3,915 open-source projects, mostly non-crashing bugs like access control flaws.

Unit 42's NOVA system analyzed 3,915 open-source projects over two months and reported 14,090 validated vulnerabilities, only 85 of which matched previously documented findings. 92% of findings fell outside fuzzing-friendly categories, clustering instead in access control, path traversal, injection, prototype pollution, and SSRF; language ecosystems showed distinct weakness profiles. Of 5,421 supply-chain findings, 1,280 were flaws in dependencies while 4,141 were downstream exposures, 2,776 validated with working proof-of-concepts. Unit 42 warned that faster discovery combined with an average 55-day patch deployment window has collapsed the patch-to-exploit gap.

Help Net Security·Aug 25, 18:03 UTC · 22d agoResearch

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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·Sep 10, 12:58 UTC · 6d agoMalware in the wild1

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MacSync Stealer: How a Google Search for Claude Led to a macOS Infostealer

Huntress dissects MacSync Stealer, a macOS infostealer delivered through fake Claude Code download pages in Google search results.

Huntress SOC analysts published a reverse-engineering analysis of MacSync Stealer, a macOS infostealer distributed through fraudulent Claude Code download pages surfaced via web searches. Users searching for Anthropic's Claude coding tool are redirected to fake download pages that install the stealer, abusing developer trust in popular AI tooling. The writeup covers the analysis of the sample and its delivery chain.

Huntress·Aug 17, 04:00 UTC · Aug 17, 2026Malware in the wild

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USN-8750-1: FFmpeg vulnerabilities

Ubuntu USN-8750-1 fixes multiple FFmpeg memory-handling flaws that allow denial of service via crafted files.

Ubuntu Security Notice USN-8750-1 patches several FFmpeg vulnerabilities related to incorrect memory operations, reported by Seung Min Shin, Xinghang Lv, and others. If a user or automated system is tricked into opening a specially crafted file, an attacker could cause a denial of service. Affected CVEs include CVE-2026-12706, CVE-2026-30999, and CVE-2026-58049.

Ubuntu Security Notices·Sep 14, 03:25 UTC · 2d agoAdvisoryCVE-2026-12706CVE-2026-30999CVE-2026-58049

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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·Sep 9, 11:05 UTC · 7d agoMalware in the wildCVE-2025-535211

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VU#369611: ExLlamaV3 contains Denial of Service vulnerability via insufficient bounds checking on kernel dispatch index

CERT/CC details CVE-2026-84286, an out-of-bounds memory access in ExLlamaV3's CUDA extension causing denial-of-service crashes; fixed via merged pull request.

CERT/CC published VU#369611 for CVE-2026-84286, an out-of-bounds memory access in the exllamav3_ext CUDA extension of the ExLlamaV3 LLM inference library. A crafted input with kernel parameter K set to 0 produces a negative index into a fixed 24-entry kernel dispatch array, causing a CUDA illegal memory access and denial-of-service crashes. The vendor fixed the issue in the main repository via pull request #310, and maintainers of 49 downstream projects, including ezexl3 and MawDiscord, are advised to rebuild against the patched version. The issue was reported by Nathan Keys and impact is limited to crashes and instability, not code execution.

CERT/CC Vulnerability Notes·Sep 11, 20:11 UTC · 5d agoVulnerabilityCVE-2026-842861

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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·Sep 9, 16:08 UTC · 7d agoExploit / PoC in the wild 2 sourcesCVE-2026-20079CVE-2026-20316

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Fake OpenAI Codex download tricks macOS users into installing malware

Cato Networks uncovered a malware campaign using sponsored search ads and fake OpenAI Codex pages to deliver an AMOS-like infostealer to macOS users.

Cato Networks researchers discovered a campaign using sponsored search results and a fake OpenAI Codex download portal on Google Sites to lure macOS users. Victims are instructed to paste a Terminal command that decodes a Base64-encoded URL and runs a multi-stage infection chain ending in a universal Mach-O binary. The delivery chain closely resembles Atomic macOS Stealer (AMOS), and related infrastructure impersonating Claude Code was also found. Operators use iframe-based hosting and path/device gating to evade analysts and automated scanners.

Help Net Security·Aug 25, 00:00 UTC · 22d agoMalware in the wild

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Honeypot-Omaha and batch.py [Guest Diary], (Wed, Sep 2nd)

A SANS ISC guest diary describes batch.py, a Python tool that consolidates honeypot logs and enriches IOCs with threat intelligence data.

Written by a SANS.edu BACS intern, the diary explains analysis of the DShield Honeypot-Omaha sensor, which uses Cowrie to emulate SSH and Telnet and log attacker activity. The author's batch.py script implements a four-phase pipeline with SHA-256-generated master and guest authentication to consolidate JSON and log files, correlate data via external APIs, and produce MITRE, CVE, geolocation, threat-score and fingerprint enrichment for investigated indicators.

SANS Internet Storm Center·Sep 3, 02:02 UTC · 13d agoTools1

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Atomic macOS (AMOS) Stealer Activity

Unit 42 details an August 2026 AMOS macOS stealer infection delivered via fake 'macOS toolkit' pages and Terminal paste commands, exfiltrating credentials to C2.

Unit 42 analyzed an AMOS (Atomic macOS Stealer) infection from August 5, 2026, initiated via a page at getmacouscloud[.]com instructing users to paste a command into Terminal. The command fetched a Zsh script from ferncore13[.]com that delivered a Mach-O installer to /tmp/helper and supporting files under /Library/Application Support/.com.apple.accountsd/ and .com.apple.metadata.mds/. AMOS collected browser data, credentials, cryptocurrency wallets (Binance, TonKeeper), Telegram data, and FileGrabber content such as AWS and gcloud files, uploading it via HTTP POST to C2 server 161.35.146[.]120. AMOS has been advertised on Telegram since April 2024 and distributed via ClickFix campaigns, malicious ads, and cracked-software sites.

Palo Alto Unit 42·10:00 UTC · 12h agoMalware in the wild

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Campaign Evolution: Darkleech to Pseudo

Unit 42 traces the pseudo-Darkleech campaign, which compromises websites to inject scripts redirecting visitors to exploit kits delivering ransomware.

Palo Alto Networks Unit 42 analyzed the evolution of the pseudo-Darkleech campaign, which injects malicious script into compromised Apache, IIS and WordPress sites to redirect visitors to exploit kits such as Angler and Neutrino. The original Darkleech Apache module infected thousands of servers starting in 2012 and delivered Blackhole EK until that kit disappeared after Paunch's 2013 arrest. From 2015 onward, pseudo-Darkleech delivered ransomware families like CryptoWall and TeslaCrypt, and by early 2016 its injected scripts added obfuscated numeric blocks with frequently changing separator characters. Unit 42 tracks these patterns to help defenders identify compromised websites.

Palo Alto Unit 42·Aug 17, 09:53 UTC · Aug 17, 2026Threat actor in the wild

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iceener/files-stdio-mcp-server: sandbox escape in fs_search via a symlinked directory (recursive walker validates only the top level)

iceener/files-stdio-mcp-server allows a read-side sandbox escape: fs_search follows symlinked directories while the recursive walker validates confinement only at the top level.

A vulnerability report describes a read-side sandbox escape in iceener/files-stdio-mcp-server, an MCP server for text-based file access that explicitly promises 'Sandboxed filesystem access. Only these paths are available'. The fs_search tool can follow symlinked directories outside the allowed paths, and the recursive directory-listing walker used by fs_search (and by fs_read) validates confinement only at the top level. The same flaw affects fs_read's directory-listing walker. No CVE identifier was assigned in the provided report text.

oss-security·Sep 10, 01:17 UTC · 6d agoVulnerability

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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·Sep 1, 14:26 UTC · 15d agoResearch

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Campaign Evolution: pseudo

Unit 42 traces the pseudo-Darkleech campaign's 2016 shift from Angler to Neutrino to Rig exploit kits and rotating ransomware payloads.

Unit 42 documents how the pseudo-Darkleech exploit kit campaign evolved through 2016, switching from Angler EK to Neutrino EK in June and to Rig EK in September after Neutrino ceased operations. Payloads rotated from TeslaCrypt to CryptXXX, CrypMIC, and finally Cerber ransomware by October 2016. Injected script on compromised websites changed from 12,000-18,000 character obfuscated blocks to short, unobfuscated hidden iframes starting July 1, 2016.

Palo Alto Unit 42·Aug 17, 09:54 UTC · Aug 17, 2026Threat actor in the wild

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Malware bypasses browser checks to force install Chrome, Edge extensions

Elastic Security Labs detailed KREMLIN, a Brazilian banking malware that silently installs malicious Chrome and Edge extensions, with 1,515 confirmed infections.

Elastic Security Labs analyzed KREMLIN, a toolkit used by a Brazilian operation in at least seven campaigns since May 2025 that impersonates 12 banks to trick users into opening a JavaScript file disguised as a bank receipt or invoice. After anti-sandbox checks, it downloads Node.js, persists via a scheduled task, and fetches payload locations from an Ethereum smart contract, hiding payloads in JPEG images on Internet Archive. The toolkit bypasses Chromium integrity mechanisms to install unapproved Chrome/Edge extensions masquerading as AVSync that steal cookies, keylog form input, capture screenshots, and intercept HTTP traffic, while recent campaigns deployed the REMCOS RAT and earlier ones Pulsar RAT. Elastic confirmed 1,515 infected systems, almost all in Brazil, and disrupted the campaign by registering an anti-sandbox canary domain; the linked wallet handled roughly 20,800 USDT incoming and 19,000 USDT outgoing.

BleepingComputer·18:50 UTC · 3h agoMalware in the wild 3 sources

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PAPERMILL Hackers Abuse Signed Notepad++ to Deploy VenomRAT in Tax Audit Attacks

PAPERMILL phishing campaign abuses a signed Notepad++ copy and tax-audit lures to deploy VenomRAT against targets in India.

JUMPSEC tracks PAPERMILL as an emerging cluster whose emails pass SPF, DKIM, and DMARC and deliver tax-audit themed disk images. The mounted image pairs a legitimately signed, renamed executable with a rogue libcurl.dll for DLL sideloading, then uses a Donut shellcode loader to run VenomRAT 6.0.3 in memory with hidden VNC, data-stealing, and file-grabbing capabilities. The loader includes anti-analysis checks and RunOnce persistence, and lures plus China-connected infrastructure overlap with the Silver Fox ecosystem, though attribution remains unconfirmed.

Cyber Security News·12:23 UTC · 10h agoPhishing & fraud in the wild 2 sources

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An Empirical Security Analysis of Open-Source Software Used in Onboard Satellite Systems

Study of 126 onboard satellite OSS repositories finds 2,827 security findings, 72% medium severity or higher, dominated by memory safety and code quality weaknesses.

Researchers performed an empirical security analysis of 126 public repositories of open-source software used in onboard satellite systems using SBOM generation, software composition analysis, static application security testing, infrastructure-as-code analysis, and secret scanning. After cleaning and deduplication the pipeline produced 2,827 findings, with medium-severity findings accounting for 49% and 72% classified medium or higher. A CWE-based taxonomy mapped all findings to eight weakness families, with Memory Safety and Code Quality dominating, followed by Input Validation and Injection. Project-developed code accounted for 81.4% of findings, though external dependency code remained relevant; findings do not establish mission-specific exploitability.

arXiv cs.CR·Sep 14, 11:54 UTC · 2d agoResearch1

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