Huntress observed a 155x increase in password spraying attacks in H1 2026, including a campaign that generated more than 81 million login attempts in two weeks. The attacks exploited legacy authentication and gaps in MFA policies that left some login flows unprotected.
Microsoft tracked over 30 MacSync Stealer domains by focusing on behavioral patterns, revealing a campaign targeting passwords, keys, wallets and other data. Domain blocking is a losing game when the thing you’re blocking can register a new domain faster than you can add it to a list. That’s the exact problem Microsoft Defender Experts ran into while tracking MacSync Stealer, a macOS-focused information stealer that RST Cloud first flagged for swapping out its command-and-control infrastructure almost immediately after getting publicly outed. Microsoft detailed how its experts stopped chasing individual domains and started tracking the behaviors that stayed constant underneath them. Instead of tracking individual domains, Microsoft looked at recurring request patterns, HTTP headers and other behaviors. This allowed its researchers to link more than 30 domains to the same campaign and determine that the infrastructure was doing more than just sending commands to infected Macs. It was also being used to collect, stage and exfiltrate stolen data. “MacSync Stealer is a macOS-focused information stealer that relies on changing infrastructure to deliver payloads, communicate with compromised devices, and exfiltrate data. Earlier reporting by RST Cloud identified the threat through a limited set of domains and documented rapid command-and-control (C2) replacement after public disclosure.” reads the report published by Microsoft. “Microsoft Defender Experts expanded that view by correlating recurring endpoints and network behaviors across the activity. This behavior-led approach connected more than 30 domains and showed that the infrastructure supported more than C2 communication, extending into active collection, staging, and exfiltration.” The infection chain starts with a trick rather than an exploit. Victims get social-engineered through a technique known as ClickFix, tricked into pasting or running commands directly in macOS Terminal, and once that shell session fires, curl pulls down attacker-controlled payload content from a path formatted as /curl/[token]. Then, native macOS tools decode and unpack the payload, and an AppleScript-driven layer takes over, blending Unix commands like sh, cp, rm, and killall with osascript calls that make the whole chain look more like ordinary system scripting than malware. Once active, the stealer focuses on valuable data. The malicious code looks for macOS Keychain data, saved browser passwords and cookies, SSH keys, AWS credentials, Kubernetes configurations and files in common user folders. It also searches for Ledger and Trezor wallet data, showing that the malware targets users with valuable credentials and assets rather than simply collecting random browser history. What actually confirms exfiltration, rather than just suspicious traffic, is the upload mechanism itself. Collected data gets staged under temporary paths, compressed into an archive, split into chunks, and pushed out through HTTP PUT requests carrying parameters like upload_id, chunk_index, and total_chunks. “The staged archive was uploaded through rotating infrastructure using curl and HTTP PUT requests. Observed requests included –data-binary, API-key headers, macOS User-Agent string, upload_id values, chunk_index values, and total_chunks parameters.” states Microsoft. “These upload traits confirmed active data exfiltration and provided durable hunting pivots even when domains rotated. “ The researchers pointed out that the exfiltration method stays recognizable even when the destination keeps changing. RST Cloud’s follow-up work backs up how consistent this infrastructure actually is under the surface. Using the same recurring URI patterns, RST Cloud surfaced eleven additional candidate domains and found a static API-key value shared across four confirmed command-and-control domains, even while the build token attached to each deployment kept rotating. A shared static key sitting inside otherwise rotating infrastructure is exactly the kind of detail that makes automated evasion look less impressive up close. The attack wraps up with cleanup, deleting temporary archives, staging folders, and lock files after the upload completes. Microsoft notes this reduces what’s left sitting on disk, but it doesn’t erase the behavioral sequence itself. “After exfiltration, the malware removed temporary archives, staging folders, lock files, and other artifacts. Although this cleanup reduced on-disk evidence, the sequence of archive creation, chunked upload, and deletion can still provide a useful behavioral correlation for defenders.” concludes Microsoft. For anyone defending Mac fleets, the practical takeaway here isn’t a list of domains to block, since that list will be stale within days. It’s building detection around the recurring shape of the attack itself: shell sessions spawning curl with those specific flag patterns, osascript chaining rapidly into network activity, and archives appearing under /tmp/sync* right before outbound PUT traffic starts. Chase the pattern, not the address, because the address was never going to sit still long enough to matter. Follow me on Twitter: @securityaffairs and Facebook and Mastodon Pierluigi Paganini (SecurityAffairs – hacking, malware)
The Cybersecurity and Infrastructure Security Agency (CISA) said Tuesday that the Medusa ransomware gang has breached more than 500 critical infrastructure organizations in the United States since June 2021. This was revealed in a joint advisory in coordination with the Department of Health and Human Services (HHS) and the Federal Bureau of Investigation (FBI). "As of April 2026, Medusa actors have impacted more than 500 victims across multiple critical infrastructure sectors, including Healthcare and Public Health, Defense Industrial Base, Critical Manufacturing, Government Services and Facilities, Information Technology, and Financial Services," they said. "Other victims include organizations in the medical, education, legal, insurance, technology, and manufacturing industries." This is an update to a joint report published in March 2025, which said the Medusa ransomware operation had impacted an estimated over 300 critical infrastructure organizations.
Cybersecurity researchers at Hunt.io have disclosed details of a campaign that they say compromised more than 14,530 Dahua devices between June 17 and July 22, 2026, using credential attacks, two authentication-bypass flaws, and a peer-to-peer (P2P) relay technique. The activity, codenamed Operation CameraSwarm, was reconstructed from a 407 MB exposed working directory containing 2,616 files
Comcast is promoting WiFi-based motion detection as a part of its new Xfinity Shield home protection platform, allowing routers and wireless devices to detect people moving through a home without cameras or motion sensors. This feature was announced as part of a new Xfinity Shield product offering on Tuesday, a new application suite that combines cybersecurity, physical home monitoring, and family safety features through Xfinity WiFi and the Xfinity app. Part of this new offering is WiFi Shield, which is included at no additional cost for Xfinity Internet customers with compatible gateways. It combines Xfinity's CyberSecure network protection, Family Settings, and WiFi Motion, with Home Watch, Away Watch, and Dark Watch modes used to control when notifications are generated. Comcast is also launching Shield Select for $15 per month, which adds an indoor camera, door/window sensor, cloud video storage, and 24/7 urgent response functionality.
A Heights Finance breach exposed personal and financial data of over 1.2 million people after hackers compromised a third-party cloud platform. Heights Finance is a U.S. consumer finance company that provides personal loans and related lending services, mainly to customers who may have limited access to traditional bank credit. It is part of Heights Finance Holdings Co. Heights Finance Holdings is notifying more than 1.2 million people that on May 7, 2026, Heights Finance discovered unauthorized access to a third-party cloud platform storing customer data. The company launched an investigation with external cybersecurity experts and notified federal law enforcement. “On May 7, 2026, Heights discovered that an unauthorized actor gained access to a cloud-based platform hosted by a third party that we use to store certain customer data. This activity was limited to the cloud-based platform only—it did not affect any of our loan management systems or other computer systems or networks. We immediately activated our incident response protocols, brought in outside cybersecurity specialists to investigate, and reported the incident to federal law enforcement.” reads the notice of data breach. “We have since confirmed that the cloud-based platform is secure and that there is no ongoing security threat. Our operations were not impacted by this incident and have continued safely and securely.” Heights said its internal systems and operations were not affected, the platform has been secured, and there is no ongoing threat. The compromised customer information included contact details, financial and bank account data, government IDs and dates of birth. The affected data varies by person and may involve Heights Finance customers, loan applicants, people who inquired about its products, or former borrowers of Curo Management and related brands. Heights Finance is offering affected individuals 24 months of free credit monitoring and identity protection. The company said dark web monitoring has found no evidence that the stolen data has been published. No threat actor has claimed responsibility, and no known ransomware or extortion group has been linked to the breach so far. Follow me on Twitter: @securityaffairs and Facebook and Mastodon Pierluigi Paganini (SecurityAffairs – hacking, Heights Finance)
A custom Java web shell likely linked to the Clop ransomware gang was designed specifically for PTC Windchill and FlexPLM servers, with built-in features to decrypt credentials, enumerate file repositories, and steal files. Cybersecurity company ReliaQuest analyzed the web shell after it is believed to have been deployed in recent data theft attacks exploiting CVE-2026-12569, a critical remote code execution vulnerability affecting PTC Windchill. ReliaQuest says the implant is not a generic web shell repurposed for the attacks, but was instead built with detailed knowledge of Windchill's internal APIs, database schema, keystore, and file-vault structure. "This appears to be an application-specific evolution of Clop's established mass-exploitation playbook," ReliaQuest said in a report shared with BleepingComputer.
Microsoft has started testing a faster File Explorer and a less cluttered and more customizable context menu in Windows 11 preview builds rolling out to Insiders this week. As the File Explorer team explained in a Monday blog post, the changes focus on improving File Explorer speed, performance, and reliability and addressing customer-reported issues. The redesigned context menu experience also aims to make it faster, reduce clutter, and make it more customizable than ever before. At the bottom of the new right-click menu, Microsoft also added a "Customize menu" shortcut to the Settings page, where users can tweak the context menu to suit their preferences. "We've continued refining File Explorer based on that feedback, removing friction and improving the details that help make everyday tasks feel more natural and predictable. For example, file renames no longer get interrupted by background file synchronization, and case-only filename changes now appear immediately," Microsoft said.
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has confirmed that ransomware gangs are also exploiting a high-severity Windows Task Host vulnerability that was flagged as actively exploited in April. Task Host is a core Windows system component that allows DLL-based processes to run in the background and prevents data corruption by ensuring they close properly during shutdown. Tracked as CVE-2025-60710, this Windows privilege escalation security flaw was patched by Microsoft in November 2025 and stems from a link following weakness that affects Windows 11 and Windows Server 2025 devices. Following successful exploitation, local attackers with basic user permissions can gain SYSTEM privileges and take full control of unpatched devices. While it didn't share any details regarding ongoing attacks and Microsoft has yet to update its security advisory to confirm in-the-wild exploitation, CISA added CVE-2025-60710 to its list of actively exploited vulnerabilities on April 13 and gave Federal Civilian Executive Branch (FCEB) agencies two weeks to secure their systems.
U.S. Cybersecurity and Infrastructure Security Agency (CISA) adds a Ray-Project Ray vulnerability to its Known Exploited Vulnerabilities catalog. The U.S. Cybersecurity and Infrastructure Security Agency (CISA) added a Progress LoadMaster vulnerability, tracked as CVE-2025-62593 (CVSS score of 9.4), to its Known Exploited Vulnerabilities (KEV) catalog. CVE-2025-62593 is a critical remote code execution (RCE) vulnerability in Ray, an AI compute engine. Versions before 2.52.0 insufficiently protected the Ray dashboard/API against browser-based attacks. Its defense relied on checking whether the HTTP User-Agent header started with “Mozilla”, but browsers can modify this header. By combining this weakness with DNS rebinding, an attacker could potentially execute arbitrary code on a developer’s machine simply by getting them to visit a malicious website or view a malicious advertisement while running Ray. The vulnerability affects Firefox and Safari. Ray 2.52.0 fixes the issue. “This vulnerability is due to an insufficient guard against browser-based attacks, as the current defense uses the User-Agent header starting with the string “Mozilla” as a defense mechanism. This defense is insufficient as the fetch specification allows the User-Agent header to be modified.” reads the advisory. “Combined with a DNS rebinding attack against the browser, and this vulnerability is exploitable against a developer running Ray who inadvertently visits a malicious website, or is served a malicious advertisement (malvertising).” “An attacker exploited a code injection vulnerability in Ray AI Compute Engine via a DNS rebinding attack, leading to remote code execution. This allowed the attacker to escalate privileges within the system, move laterally across the network, establish command and control channels, exfiltrate sensitive data, and ultimately disrupt operations.” reads the analysis published by Aviatrix. According to Binding Operational Directive (BOD) 22-01: Reducing the Significant Risk of Known Exploited Vulnerabilities, FCEB agencies have to address the identified vulnerabilities by the due date to protect their networks against attacks exploiting the flaws in the catalog. Experts also recommend that private organizations review the Catalog and address the vulnerabilities in their infrastructure. CISA orders federal agencies to fix the vulnerability by the end of this week, on August 20, 2026. Follow me on Twitter: @securityaffairs and Facebook and Mastodon Pierluigi Paganini (SecurityAffairs – hacking, CISA)
Confirm this action.
Leaving now will discard your changes.