Security Experts:

Connect with us

Hi, what are you looking for?


Application Security

Microsoft Confirms New Windows XP Zero-Day Under Attack

UPDATE: Microsoft late Wednesday confirmed a Windows kernel zero-day vulnerability is being exploited in “limited, targeted attacks” against Windows XP users.

UPDATE: Microsoft late Wednesday confirmed a Windows kernel zero-day vulnerability is being exploited in “limited, targeted attacks” against Windows XP users.

Microsoft issued a security advisory to acknowledge the flaw after anti-malware vendor FireEye warned that the Windows bug is being used in conjunction with an Adobe Reader exploit to infect Windows machines with malware.

Microsoft described the issue as an elevation of privilege vulnerability that allows an attacker to run arbitrary code in kernel mode. An attacker could then install programs; view, change, or delete data; or create new accounts with full administrative rights.

The vulnerability cannot be used for remote code execution but could allow a standard user account to execute code in the kernel. Currently, the exploit appears to only work in Windows XP, FireEye said.

The exploit targets Adobe Reader 9.5.4, 10.1.6, 11.0.02 and prior on Windows XP SP3. Windows users running the latest versions of Adobe Reader are not be affected by this exploit.

Microsoft’s advisory includes some “workarounds” to help Windows XP and Windows Server 2003 users mitigate the issue.

In addition, FireEye recommends that Windows users upgrade to the latest version of Adobe Reader to blunt the in-the-wild PDF exploit. 

Anti-malware vendor Symantec also confirmed the attacks have been ongoing since the beginning of November this year.  The company said the attack arrives as a malicious PDF file with file names such as syria15.10.pdf or Note_№107-41D.pdf either via attachments or via downloads from rigged websites.

“Upon successful exploitation of the vulnerability, another malicious file, observed since mid-October, is dropped onto the compromised computer. This Trojan collects system information and connects to a command-and-control (C&C) server,” the company said.

Symantec has spotted infections in India, Australia, United States, Chile, Hungary, Germany, Norway, and Saudi Arabia.

*Updated with additional details from Symantec

Written By

Ryan Naraine is Editor-at-Large at SecurityWeek and host of the popular Security Conversations podcast series. He is a security community engagement expert who has built programs at major global brands, including Intel Corp., Bishop Fox and GReAT. Ryan is a founding-director of the Security Tinkerers non-profit, an advisor to early-stage entrepreneurs, and a regular speaker at security conferences around the world.

Click to comment

Expert Insights

Related Content

Application Security

Cycode, a startup that provides solutions for protecting software source code, emerged from stealth mode on Tuesday with $4.6 million in seed funding.

Malware & Threats

Microsoft plans to improve the protection of Office users by blocking XLL add-ins from the internet.

Cloud Security

VMware vRealize Log Insight vulnerability allows an unauthenticated attacker to take full control of a target system.

Mobile & Wireless

Technical details published for an Arm Mali GPU flaw leading to arbitrary kernel code execution and root on Pixel 6.

Mobile & Wireless

Apple rolled out iOS 16.3 and macOS Ventura 13.2 to cover serious security vulnerabilities.

Mobile & Wireless

Apple’s iOS 12.5.7 update patches CVE-2022-42856, an actively exploited vulnerability, in old iPhones and iPads.


Security researchers have observed an uptick in attacks targeting CVE-2021-35394, an RCE vulnerability in Realtek Jungle SDK.


Google has awarded more than $25,000 to the researchers who reported the vulnerabilities patched with the release of the latest Chrome update.