Are you still using Windows XP? In its latest Threat Report, security vendor F-Secure warns that a powerful zero-day attack against Windows XP is a matter of when—not if—and provides some guidance for those stalwart (or foolhardy) PC warriors who plan to ignore the April 8 “XPocalypse” when Microsoft support for the OS officially expires.

To be fair, F-Secure does not take a “sky is falling” approach to the end of Windows XP support, but advises that “folks that continue to use XP at home can do so with some reasonable amount of safety, for a while still, but they absolutely need to review their Internet (particularly Web browsing) and computing habits.”

F-Secure's warning is echoed from most security experts, as well as from Microsoft itself. A Microsoft blog post points out that malware developers will simply reverse-engineer patches and updates for other versions of Windows and test to see if those same flaws exist in XP. If they do, attackers will develop exploits and it will be open season on the legacy platform.

The F-Secure report provides some specific measures to reduce security risks, such as installing the final updates for Windows XP from Microsoft, making sure Microsoft Office is fully patched, ensuring that third-party software is patched and updated, and using a firewall and antimalware protection. All of the suggestions provided by F-Secure are actually things that anyone running any version of Windows should be doing on a regular basis.

The report points out that Windows XP security is a serious issue because once the OS is compromised, it’s significantly more difficult to clean and repair than other versions of Windows. The final piece of advice F-Secure provides is really the best: Consider upgrading your operating system.

The F-Secure H2 2013 Threat Report goes beyond Windows XP security, though. Mikko Hypponen, Chief Research Office for F-Secure, elaborates on his concerns about government surveillance in the report’s foreword. Hypponen cautions that oversharing on social networks today may come back to haunt you later—especially if you plan to run for public office in a decade or two.

Windows XP security is a serious issue because once the OS is compromised, it’s significantly more difficult to clean and repair than other versions of Windows.

“Government surveillance is not about governments collecting the information you’re sharing publicly and willingly,” warns Hypponen. “It’s about collecting the information you don’t think you’re sharing at all.”

The topic is a sensitive one throughout the security industry and particularly for Hypponen. He was slated to present at the recent RSA Security Conference and became one of the more high profile protesters when he pulled out after allegations that the RSA had collaborated with the NSA. He still gave his presentation, but it was to an invitation-only media audience at a luncheon or at the TrustyCon counter-conference that was held nearby.

The F-Secure Threat Report's Incidents Calendar breaks down the major security events of the year—segregated into categories: Hacks & Espionage, Security & Enforcement, and Malware & Vulnerabilities.

According to F-Secure, Web-based malware attacks doubled in the second half of 2013 compared with the first half. The report also notes that Java-related exploits declined during the second half of 2013, but still make up the second-most reported type of threat. The F-Secure report also notes that 97 percent of the mobile malware threats in 2013 were targeted at Android—data that mirrors the information from the recent Fortinet Threat Landscape report .

For complete details, check out the full F-Secure H2 2013 Threat Report.