Latest cybersecurity reporting from selected sources.

From late April 2026 to mid-June 2026, Microsoft Defender Experts observed increased ACR Stealer activity across customer environments. These campaigns are successfully using ClickFix lures to steal browser credentials, authentication tokens, and sensitive documents from enterprise environments. The post ACR Stealer: Two observed intrusion chains amid increased threat activity appeared first on Microsoft Security Blog.

At least two distinct threat actors are weaponizing a novel evasion technique called OAuth client ID spoofing in cloud campaigns, while slipping past telemetry

Sophos looked at a week of its own endpoint data and found that AI coding agents such as Claude Code, Cursor, and OpenAI Codex are setting off detection rules written to catch human intruders

Microsoft shut down the StegoAd campaign, which used 119 malicious Edge extensions, hit 2.6M installs, and ran undetected for two years. Microsoft just shut down one of the more technically clever malicious extension campaigns it’s ever documented. The operation, named StegoAd, ran 119 extensions on the Edge Add-ons store, racked up roughly 2.6 million installs, […]

Microsoft has shut down a long-running malicious extension operation on the Edge Add-ons store that hid its payloads inside ordinary image and font files, then woke up days after install to steal credentials and run ad fraud

A coordinated law enforcement operation, in partnership with private sector companies, including Bitdefender, Bitsight, ESET, and Microsoft, has resulted in the takedown of criminal infrastructure powering Amadey and StealC

Microsoft researchers have detailed an exploit chain, named AutoJack, that turns an AI browsing agent into a delivery vehicle for remote code execution

The Miasma worm compromised 73 Microsoft GitHub repos, spreading via AI coding tools and stealing cloud credentials from developers and CI/CD systems. A self-replicating worm called Miasma has compromised 73 Microsoft GitHub repositories and forced GitHub staff to disable them. The affected repos include core Azure infrastructure like azure-functions-host and the entire Durable Task family […]

Attackers Compromised More Than 70 Microsoft Repositories in Under 2 MinutesAttackers linked to the Miasma supply-chain campaign compromised a Microsoft contributor account and pushed malicious code into more than 70 repositories, using artificial intelligence-assisted coding tools as an infection path to steal credentials and developer secrets at scale.

A large-scale npm supply chain attack compromised over 90 versions of @redhat-cloud-services packages, silently infecting CI/CD environments and developer systems. The malicious code steals credentials from GitHub, cloud platforms, and local machines, then spreads like a worm by republishing trusted packages. Discover how the attack works, what data is at risk, and the steps you can take to protect your organization. The post Preinstall to persistence: Inside the Red Hat npm Miasma credential-stealing campaign appeared first on Microsoft Security Blog.

The Mini Shai-Hulud campaign used malicious npm packages to target cloud and CI/CD credentials across developer environments. This report details the attack chain, detection opportunities, and mitigation guidance to help organizations identify and disrupt related activity. The post Typosquatted npm packages used to steal cloud and CI/CD secrets appeared first on Microsoft Security Blog.

A multi-stage attack on Linux devices began with an exposed F5 BIG-IP edge appliance and pivoted to an internal Confluence server for credential theft and identity compromise. Learn how the threat actor attempted Kerberos relay and lateral movement, and how Microsoft Defender detected, blocked, and unraveled the attack. The post From edge appliance to enterprise compromise: Multi-stage Linux intrusion via F5 and Confluence appeared first on Microsoft Security Blog.

Consider a cached access key on a single Windows machine. It got there the way most cached credentials do - a user logged in, and the key stored itself automatically. Standard AWS behavior. No one misconfigured anything or violated a policy. Yet that single key, which was easily accessible to a minor-league attacker, could have opened a path to some 98% of entities in the company's cloud

Compromised @antv npm packages deploy the Mini Shai-Hulud payload to steal CI/CD secrets from Linux-based automation environments. The malware executes during npm install and targets credentials across GitHub, AWS, Kubernetes, Vault, npm, and 1Password platforms. The post Mini Shai Hulud: Compromised @antv npm packages enable CI/CD credential theft appeared first on Microsoft Security Blog.

Cybersecurity researchers have flagged a compromised version of the Nx Console extension that was published to the Microsoft Visual Studio Code (VS Code) Marketplace

Storm-2949 turned stolen credentials into a cloud-wide breach, moving from identity compromise to large-scale data theft without using malware. This incident shows how threat actors can exploit trusted systems to operate undetected. The post How Storm-2949 turned a compromised identity into a cloud-wide breach appeared first on Microsoft Security Blog.

The Iranian state-sponsored hacking group known as MuddyWater (aka Mango Sandstorm, Seedworm, and Static Kitten) has been attributed to a ransomware attack in what has been described as a "false flag" operation

Cybersecurity researchers have disclosed details of an intrusion that involved the use of a CloudZ remote access tool (RAT) and a previous undocumented plugin dubbed Pheno with the aim of facilitating credential theft

Microsoft researchers warn of a large-scale phishing campaign using fake compliance emails to steal credentials, targeting 35,000 users across 13,000 organizations worldwide

Microsoft has disclosed details of a large-scale credential theft campaign that has leveraged a combination of code of conduct-themed lures and legitimate email services to direct users to attacker-controlled domains and steal authentication tokens