PIF file type meaning

When it comes to file types you should never trust, PIF belongs high on the list. PIF used to be an important file type, but it’s largely obsolete today. But if you’re curious, here’s the PIF file type meaning.

Get ready for a trip down computing history lane. But this once-important file format is risky today. In all honesty, it’s largely outlived its usefulness in most instances.

Program Information File: Inherited from Topview

PIF file type meaning
Early 16-bit versions of Windows used PIF files to set parameters so DOS applications could run correctly in a windowed, multitasking environment. That functionality is obsolete in modern versions of Windows. Corporate environments have little to lose and much to gain by blocking PIF files today. Image credit: Thinkpublic/Flickr 

The meaning of PIF file is pretty simple. PIF stands for program information file. It originated in a piece of 1980s software from IBM called Topview, which provided a type of multitasking windowed environment that ran on top of DOS. Like early versions of Windows, it was an operating environment, or shell that enhanced DOS, but not a true operating system. Topview used PIF files to store parameters for Topview to use when running DOS programs, like how much memory to use, and how to title the window.

IBM maketed Topview pretty much the way they marketed everything: badly. So Topview didn’t set the world on fire. When Microsoft designed Windows, they adopted the PIF format and extended it to include additional information Windows might need when running legacy text-mode DOS programs like Wordperfect and Lotus 1-2-3. This gave people a reason to run Microsoft Windows before native Windows software came out. But in practice, Windows didn’t really catch fire itself until 1990, with the release of Windows 3.0.

Even still, in the early 1990s there were a lot of legacy DOS applications people wanted to run in Windows. So configuring and tweaking PIFs was something power users got used to doing. It was less common under Windows 95 and 98, though still possible. By the late 90s, viable replacements for most DOS productivity software existed, so tweaking PIFs became a lost art. DOS games remained common a while longer, but most DOS games liked to run in DOS itself, not inside Windows, for maximum performance. There wasn’t much reason to use PIF files with those.

Why PIF is a risky file extension today

The question of the PIF file type meaning ought to be moot today, because there’s no longer much reason for it. DOS software won’t even run natively in modern 64-bit versions of Windows. The problem is that modern versions of Windows treat files with the PIF file extension differently than 16-bit versions did. Double clicking a PIF file sends it to the shellexecute function, which doesn’t inspect the contents. So you can rename other types of executable files, such as an exe file, to have a pif file extension, and Windows will still run it without asking questions.

This makes PIF files a great place to hide malicious code. In fact, the file type is so obscure today, you should always treat PIF files with suspicion. There’s no legitimate reason to need to change one executable file’s extension to another one except to try to hide something or be evasive. If you’re not running DOS programs under Windows 3.x or 9x on a vintage PC, you don’t need to use PIF files.

The only time I’ve ever seen PIF files in use in the last 20 or so years was when security professionals were trying to play tricks on one another.

PIF file type meaning for security professionals today

When it comes to advice for security professionals, we can sum up the PIF file type meaning simply: PIF is a file type that you might as well filter everywhere you can. Don’t allow it as an e-mail attachment. Don’t allow it to come through your web proxy, or any other place data might enter your network. There’s just no reason to allow it except from trusted software vendors, and even they won’t have much reason to use it anymore, if any.

Configuring your DLP software to block access to PIF files altogether would also be a good security measure. This is highly unlikely to interfere with anything legitimate today. But it will provide an additional way to block malware if your other security measures fail.

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