57
60
57
57
57
47
57
57
57
57
57
57
57
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.
72
FBI Disrupts China-Linked QTFY Infrastructure Used to Steal Data From U.S. Organizations
FBI and Lumen disrupted QTFY's QScan and QTRouter botnet platforms used by Chinese state-sponsored hackers to conceal intrusions into U.S. agencies.
The U.S. DoJ announced court-authorized seizure of domains behind QScan and QTRouter, operated by the Chinese state-sponsored group QTFY and employed by Nanjing Xinjiuwei Network Technology Company. QTFY has been active since May 2018 and targeted NASA, the Federal Reserve, the Department of Energy, DoJ, HHS, NIH, the U.S. Senate, and academic institutions. QScan exploits vulnerable IoT devices, feeding them into QTRouter, an OpenWrt-based proxy obfuscation network likened to an operational relay box (ORB) that masks attack origins. The group exploited zero-days such as Ivanti CSA flaws CVE-2024-8190, CVE-2024-8963, and CVE-2024-9380, plus numerous N-days, and maintained persistence with RATs, web shells, and legitimate credentials.
78
⚡ Weekly Recap: AI-Powered PLC Attacks, GitLab Attacks, Stripe Key Leaks and More
US agencies warn of AI-assisted attacks on exposed Siemens PLCs; the week also saw GitLab CVE-2026-19478 exploited and trojanized npm packages found.
The weekly recap leads with a US government warning that threat actors use AI-generated scripts and Censys/ZoomEye scanning to attack internet-exposed Siemens S7 PLCs in water, energy and manufacturing, calling it an active threat. Other stories include active exploitation of GitLab CVE-2026-19478 (CVSS 9.4, unauthenticated project rewriting), 14 trojanized npm packages delivering the RedC2 4.0 Linux backdoor, and the Zombie Card attack that revives expired Visa cards for contactless payment fraud. It also covers suspected Russian clusters UNC6293, UNC7005 and UNC5976 phishing campaigns, a faster Cloudflare Workers Spectre JWT leak, and a bespoke Cl0p JSP web shell deployed after exploiting PTC Windchill flaws.
65
Officials disrupt Chinese espionage operation that hit multiple federal agencies
FBI and DOJ seized QTFY infrastructure, disrupting a Chinese state-sponsored group that compromised federal agencies and critical infrastructure since 2018.
Authorities seized three domains powering QScan and QTRouter, the hacking suite of QTFY, a Chinese government-funded group operating through front company Nanjing Xinjiuwei Network Technology. Targets include the Departments of Energy, Justice, and Health and Human Services, the Federal Reserve, NASA, NIH, financial institutions, defense contractors, utilities, telecoms, and hospitals; the group exploited zero-days in Ivanti, Pulse Secure, Fortinet, Citrix, and others, intruding three DOE national labs in September 2024. QScan carried over 200 proof-of-concept exploits and processed more than two million scanning tasks in a single day in 2024.
88
FBI Seizes China-Linked Hacking Platforms QScan and QTRouter Used Against Critical Infrastructure
FBI seizes China-linked QScan and QTRouter hacking platforms used by QTFY to obfuscate intrusions against US federal agencies.
The DOJ and FBI seized domains hard-coded into QScan and QTRouter, two platforms operated by China-based Nanjing Xinjiuwei Network Technology Company on behalf of state-sponsored group QTFY. QScan automatically infected thousands of IoT devices which were added to QTRouter, an obfuscation network routing malicious traffic through compromised and proxy devices outside China. Targets included NASA, the Federal Reserve, Departments of Energy, Justice, and HHS, NIH, and the US Senate, exploiting flaws in Fortinet SSL-VPN, Citrix ADC, Microsoft Exchange, F5 BIG-IP, Log4j, and others.
78
Medusa ransomware gang has hit over 500 organizations, CISA warns
FBI, CISA, and HHS warn Medusa ransomware has hit over 500 organizations across critical infrastructure since June 2021, using phishing and unpatched flaws.
An updated joint advisory from CISA, FBI, and HHS states Medusa ransomware has affected more than 500 organizations, spanning healthcare, defense, manufacturing, government, IT, financial services, education, insurance, and legal sectors. Since early 2023 Medusa has operated a ransomware-as-a-service affiliate model and buys access from initial access brokers for $100 to $1 million. Affiliates gain entry via phishing and unpatched internet-facing software, exploiting newly disclosed flaws in ScreenConnect, Fortinet EMS, Fortra GoAnywhere, and BeyondTrust within 24 hours. The group runs double extortion, giving victims 48 hours before leak-site publication, with $10,000 in cryptocurrency buying a one-day delay.
75
More than 200 victims of Medusa ransomware identified over the last year, CISA says
CISA and FBI update Medusa ransomware advisory, reporting more than 500 total victims and warning the gang operationalizes newly disclosed exploits within 24 hours.
CISA and the FBI updated their March 2025 advisory, stating Medusa actors had hit more than 500 victims as of April 2026, up from 300 in 2025, with a focus on healthcare and critical infrastructure. The agencies say Medusa rapidly adopts newly announced exploits, sometimes using them up to a week before public vulnerability disclosure, but does not develop its own zero-days, preferring access obtained from unknown sources. The gang moved to an affiliate model in 2023, offers up to $1 million for exclusive initial access brokers, and uses credential stealers plus legitimate remote access tools including AnyDesk, Atera, ConnectWise and Splashtop. No new victims have appeared on its leak site since April, after the shutdown of the University of Mississippi Medical Center drew significant law enforcement attention.
70
Medusa ransomware tallies hundreds of new victims, says updated advisory on group’s tactics
CISA, FBI, and HHS updated their Medusa ransomware advisory, reporting over 500 victims and detailing the gang's access-broker and exploit tactics.
A joint advisory update from CISA, the FBI, and HHS expands the March 2025 Medusa guidance, drawing on a year of FBI investigations. The ransomware-as-a-service group's known victim tally grew from more than 300 to more than 500 between March 2025 and April 2026, with the Healthcare and Public Health sector frequently hit. Medusa pays access brokers $100 to $1 million, has exploited flaws such as Fortra GoAnywhere and BeyondTrust vulnerabilities, and leverages newly announced exploits within 24 hours, sometimes a week before public disclosure. The group uses living-off-the-land techniques, remote monitoring and management software, and RDP for lateral movement, and has been linked to actors including Microsoft-tracked Storm-1175 and North Korean hackers targeting healthcare.
72
57
57
60
60
57
57
57
Fog ransomware attack on Asia financial org draws attention over use of employee monitoring software
57
60
57
57
42
57
57
57
42