Last updated: August 19, 2026 at 1:47 AM UTC
All 741 Vulnerability 286 Breach 129 Threat 319 Defense 7
Tag: fingerprinting (2 articles)Clear

macOS ClickFix campaign fingerprints visitors to hide its malware from analysts

Microsoft Threat Intelligence detailed a macOS ClickFix operation spanning more than 250 domains that now fingerprints visitors before deciding whether to show a malware lure. The server-side gate hides the malicious page from crawlers and sandboxes while presenting selected Mac users with a fake software download, an anti-analysis layer rather than a change to the attack itself. The lure still requires the victim to copy and run an obfuscated command in Terminal, which fetches scripts and installs an infostealer, in this case Atomic Stealer, that targets credentials, browser data, authentication stores, and cryptocurrency wallets. Many domains follow a dictionary-word naming pattern using the word file.

Check
Warn Mac users never to paste and run Terminal commands from a web verification or fix prompt, and use the file-plus-dictionary-word domain pattern as a threat-hunting pivot.
Affected
macOS users who follow fake software-fix prompts; the fingerprinting gate hides the lure from analysis while serving selected victims an infostealer that harvests credentials, browser data, and crypto wallets.
Fix
Update to macOS 26.4 for its new Terminal and XProtect protections, block known campaign domains, monitor endpoints for scripts run from Terminal, and reinforce that legitimate fixes never require pasted commands.

Unpatched Adobe Reader zero-day exploited since December - malicious PDFs steal data with zero clicks

An unpatched zero-day in Adobe Acrobat Reader has been actively exploited since at least November 2025 using booby-trapped PDF documents. The exploit, discovered by EXPMON researcher Haifei Li, works on the latest version of Adobe Reader without any user interaction beyond opening the file. It abuses privileged Acrobat JavaScript APIs (util.readFileIntoStream and RSS.addFeed) to silently harvest local files, OS details, language settings, and the Reader version from the victim's machine, then sends everything to an attacker-controlled server. The PDFs use Russian-language lures related to the oil and gas industry. The attack is a two-stage operation: the first pass fingerprints the target, and if the system meets the attacker's criteria, a follow-on RCE or sandbox escape payload is delivered. Only 5 out of 64 antivirus engines on VirusTotal detected the sample. No CVE has been assigned and no patch is available.

Check
Warn staff not to open PDF attachments from unknown or unexpected sources until Adobe releases a patch. This is especially urgent because the exploit requires no interaction beyond opening the file.
Affected
All current versions of Adobe Acrobat Reader on Windows and macOS. The exploit was confirmed working on Adobe Reader version 26.00121367, the latest at time of discovery.
Fix
No patch available yet - Adobe has been notified but has not released a fix. Immediate mitigations: disable JavaScript in Adobe Reader (Edit > Preferences > JavaScript > uncheck 'Enable Acrobat JavaScript'). Block outbound HTTP/HTTPS traffic containing 'Adobe Synchronizer' in the User-Agent header. Block the known C2 IP 169.40.2.68 on port 45191. Consider switching to an alternative PDF reader (like Foxit or browser-based viewing) until Adobe patches.