MicrosoftDefender, Windows’ built-in antivirus tool, is widely considered robust enough to mean that an average user no longer needs a third-party antivirus orsecuritysuite. However, a bug brought to light by Twitter/X useryappyshows that there are times when Microsoft Defender can be extremely overzealous in its attempts to defend your computer.

A false positive can be observed when you type ‘This content is no longer available.’ or ‘This content is no longer available!’ in Notepad and save it as a text file on your PC. When you do so, Microsoft Defender will instantly flag it as a Trojan file and delete it from your system - no matter what file name you use, ostensibly protecting you from a potential ‘severe threat.’

False positive

my gf just found out that a text file solely containing the string “This content is no longer available.” trips up windows defender lol pic.twitter.com/8RyHW3nltVJune 21, 2024

Upon first investigation, yappy and some other Tweet/Xers concluded that the cause of the false positive was an SHA-256 collision. However, the astronomical odds against such a clash rung true, as most commenters now agree the headlining text string was used in several previous threats, and thus raises a red flag in the Windows Defender detection engine.

False positive

This head-scratching bug isn’t the first time Microsoft has had issues with its Defender antivirus. Microsoft actuallybroke it in 2020 with a faulty update, while itpatched a serious bug in 2019that prevented the antivirus app from operating properly. But aside from these missteps, we stillconsider Microsoft Defender as a pretty good antivirus.

Thankfully, this bug isn’t as serious as those issues, as the text line doesn’t pose any actual threat toWindows 11. Furthermore, if you add other text to it (like changing punctuation or adding an extra space at the end), the false detection goes away. However, in the unlikely event that you must have this exact text string saved on a text file on your computer, you need to exclude the folder where you’re saving it from scans, otherwise, it’ll be gone the moment you hit Ctrl + S.

Jowi Morales

Hopefully, Microsoft can fix this silly bug soon. This isn’t a threat to the security of Windows 11 and we don’t think anyone will want to temporarilydisable Microsoft Defenderand install another antivirus program waiting for a fix. Meanwhile, Kaspersky has recently become even less attractive as an alternative, asWashington has just sanctioned it.

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Jowi Morales is a tech enthusiast with years of experience working in the industry. He’s been writing with several tech publications since 2021, where he’s been interested in tech hardware and consumer electronics.