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ZDI-26-605: Microsoft Windows Localized Filenames Improper Input Validation NTLM Response Information Disclosure Vulnerability

ZDI advisory ZDI-26-605 details an improper input validation flaw (CVE-2026-50508, CVSS 3.3) in Microsoft Windows localized filenames that leaks NTLM responses.

The Zero Day Initiative released advisory ZDI-26-605 describing improper input validation in Microsoft Windows handling of localized filenames. Remote attackers can disclose NTLM authentication responses if the target opens a malicious file or visits a crafted page. ZDI rated the issue CVSS 3.3 and assigned CVE-2026-50508. Leaked NTLM responses could enable offline credential cracking.

ZDI Published Advisories · 23d agoAdvisoryCVE-2026-505081

ZDI-26-606: Microsoft Windows Compatibility Appraiser Link Following Local Privilege Escalation Vulnerability

ZDI disclosed a link-following flaw in Windows Compatibility Appraiser (CVSS 7.0) enabling local privilege escalation from the LOCAL SERVICE context.

ZDI-26-606 describes a link-following vulnerability in the Windows Compatibility Appraiser component that permits local privilege escalation. An attacker must already be able to execute low-privileged code in the LOCAL SERVICE context on the target system. ZDI rated the issue 7.0 on the CVSS scale; the advisory lists no CVE identifier. No active exploitation is reported.

ZDI Published Advisories · 23d agoVulnerability2

Malspam Targeting Brazil Continues to Evolve

Brazilian malspam campaigns continue evolving, abusing Google URL shortener and Dropbox and using Squiblydoo plus DLL side-loading to deploy likely infostealing botnet malware.

A June 2017 Brazilian malspam campaign spoofed IPTU tax notification emails, using the recipient's address as the sender, and abused Google's URL shortener and Dropbox to deliver a zip containing a malicious Windows shortcut (.lnk) file. The LNK used the Squiblydoo technique (regsvr32.exe) to download and execute a scriptlet with elevated privileges, retrieving a signed G-Buster Browser Defense executable alongside a malicious fltLib.dll loaded via side-loading, likely an information-stealing botnet. Post-infection HTTP traffic exposed over 400 infected Windows hosts, mostly in Brazil, with 2,132 Banload-tagged samples observed in the first half of 2017.

Palo Alto Unit 42 · Aug 17, 2026Malware in the wild

Decline in Rig Exploit Kit

Rig exploit kit activity dropped roughly 75% after the pseudo-Darkleech and EITest campaigns stopped using EKs, reflecting an overall decline in exploit kit activity.

Rig EK activity fell sharply in 2017: the pseudo-Darkleech campaign disappeared at the end of March, cutting Rig traffic about 50%, and the EITest campaign switched to tech support scams in late April, cutting another 50% in May. Broader causes include a shrinking browser target base, no major EK zero-day in over a year, and community takedowns of domain shadowing infrastructure. Criminals are shifting to malspam, social engineering schemes like fake HoeflerText notifications, and tech support scams.

Palo Alto Unit 42 · Aug 17, 2026Exploit / PoC in the wild1

"Blank Slate" Campaign Takes Advantage of Hosting Providers to Spread Ransomware

Unit 42 profiles the Blank Slate malspam campaign: blank emails with double-zipped attachments delivering Cerber ransomware while cycling abused hosting provider domains.

The Blank Slate campaign sends empty emails containing double-zipped archives with macro-enabled Word documents or JavaScript files that launch PowerShell to download ransomware, primarily Cerber, and occasionally Sage 2.0 or Locky. Unit 42 observed 555 campaign domains over seven months, with actors repeatedly registering new domains and cycling abuse of legitimate hosting providers after takedowns. In a five-day January-February 2017 window, at least eight domains across seven IP addresses were observed hosting Cerber payloads.

Palo Alto Unit 42 · Aug 17, 2026Threat actor in the wild1