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The Cyber Security Agency of Singapore (CSA) has issued a bulletin warning of a maximum-severity security flaw in SmarterTools SmarterMail email software that could be exploited to achieve remote code execution. The vulnerability, tracked as CVE-2025-52691, carries a CVSS score of 10.0. It relates to a case of arbitrary file upload that could enable code execution without requiring any

The threat actor known as Silver Fox has turned its focus to India, using income tax-themed lures in phishing campaigns to distribute a modular remote access trojan called ValleyRAT (aka Winos 4.0). "This sophisticated attack leverages a complex kill chain involving DLL hijacking and the modular Valley RAT to ensure persistence," CloudSEK researchers Prajwal Awasthi and Koushik Pal said in an

Artificial intelligence (AI) is making its way into security operations quickly, but many practitioners are still struggling to turn early experimentation into consistent operational value. This is because SOCs are adopting AI without an intentional approach to operational integration. Some teams treat it as a shortcut for broken processes. Others attempt to apply machine learning to problems

The Chinese hacking group known as Mustang Panda has leveraged a previously undocumented kernel-mode rootkit driver to deliver a new variant of backdoor dubbed TONESHELL in a cyber attack detected in mid-2025 targeting an unspecified entity in Asia. The findings come from Kaspersky, which observed the new backdoor variant in cyber espionage campaigns mounted by the hacking group targeting

KrebsOnSecurity.com celebrates its 16th anniversary today! A huge “thank you” to all of our readers — newcomers, long-timers and drive-by critics alike. Your engagement this past year here has been tremendous and truly a salve on a handful of dark days. Happily, comeuppance was a strong theme running through our coverage in 2025, with a primary focus on entities that enabled complex and globally-dispersed cybercrime services. Image: Shutterstock, Younes Stiller Kraske. In May 2024, we scrutinized the history and ownership of Stark Industries Solutions Ltd., a “bulletproof hosting” provider that came online just two weeks before Russia invaded Ukraine and served as a primary staging ground for repeated Kremlin cyberattacks and disinformation efforts. A year later, Stark and its two co-owners were sanctioned by the European Union, but our analysis…

KrebsOnSecurity.com celebrates its 16th anniversary today! A huge “thank you” to all of our readers — newcomers, long-timers and drive-by critics alike. Your engagement this past year here has been tremendous and truly a salve on a handful of dark days. Happily, comeuppance was a strong theme running through our coverage in 2025, with a primary focus on entities that enabled complex and globally-dispersed cybercrime services. Image: Shutterstock, Younes Stiller Kraske. In May 2024, we scrutinized the history and ownership of Stark Industries Solutions Ltd., a “bulletproof hosting” provider that came online just two weeks before Russia invaded Ukraine and served as a primary staging ground for repeated Kremlin cyberattacks and disinformation efforts. A year later, Stark and its two co-owners were sanctioned by the European Union, but our analysis…

Last week’s cyber news in 2025 was not about one big incident. It was about many small cracks opening at the same time. Tools people trust every day behave in unexpected ways. Old flaws resurfaced. New ones were used almost immediately. A common theme ran through it all in 2025. Attackers moved faster than fixes. Access meant for work, updates, or support kept getting abused. And damage did not