When Antivirus Software Flags the Wrong Files or Misses the Threat


We are all reminded to use antivirus solutions to protect our devices. However false positive and false negative flags are two antivirus errors that can happen during scanning. These errors wrongly categorize a good file as bad and a bad file as good. Always keep an eye on protection measures to avoid the trap.

Antivirus software is part of the standard toolkit for online security, constantly scanning our computers for threats.

Usually, if the antivirus finds any computer viruses, malware, or infected files in the system, it asks to remove, repair, or quarantine the file.

If no files or viruses are detected, the antivirus software also shows an ‘all-clear’ result.

However, this story may not always be the same. Antivirus tools (however good they are) can show wrong and flawed results to their users — or false positive and false negative results.

What Are False Positive Antivirus Results?

A “false positive” occurs when an antivirus program incorrectly labels a legitimate file or software as malicious within the system. Although infrequent, antivirus software can mistakenly identify a file or software as dangerous, even when there is no actual risk of harm.

While most antivirus programs effectively remove harmful files or software, the wrong removal of legitimate files or software creates unnecessary anxiety or work when there is no genuine threat.


It can also lead to the loss of critical data if the antivirus software deletes important files, and retrieving them from a (hopefully recent) backup can be time-consuming.

What are False Negative Antivirus Results?

The “false negative” presents the opposite scenario. Antivirus programs fail to recognize a malicious file or software during scanning, leading you to think the clear of malware, leaving the malicious file sitting there unnoticed.

When the antivirus cannot identify a risk, users are left unaware of the extent of damage inflicted upon their device.

Instances of false negatives in antivirus protection grant malicious files or software entry into the system or network, as the antivirus solution wrongly categorizes them as legitimate items.

The Reasons Behind Antivirus Errors

There are some common factors at work behind this antivirus malfunction. These are:

  • Software Updates

Software updates install essential security patches and bug fixes, but they can pose a risk too.

Updating the antivirus program might lead to new errors, triggering false positives and negatives on the device.

On the flip side, irregular or absent updates to the antivirus can result in false positive and false negative errors, often from the use of outdated malware and virus databases.

  • Undetected Malware

Some malware is designed to break antivirus detection, with cybercriminals constantly hunting for new ways to evade being noticed.

How To Prevent False Scanning Reports

Antivirus often quarantines files that it marks as malware instead of deleting them.

In these cases, you can manually check the file, noting its filename and the source on the disk and using online sources to verify whether it is actual malware or a false positive.

Other steps to always keep in mind, especially if you get regular erroneous flags:

  • Contact the Antivirus Provider

If you have an antivirus solution that provides many false positive results at scanning, you can send samples of the files to the antivirus manufacturer company for verification. Alternatively, you add exceptions to a whitelist or shift to another antivirus solution.

  • Keep Antivirus Software Updated

False negatives are critical. Keeping antivirus software updated will help spot emerging threats.

  • Avoid Free Antivirus Solutions

People often tend to use free antivirus software over paid ones. But most lack the required most up-to-date security features. A free antivirus is less likely to efficiently detect malicious files or programs.

  • Reporting Software Bugs

Enabling the option to send bug reports to the vendor of the antivirus solution can help the developers improve their software. Bugs can be quickly fixed by installing patches.

The Bottom Line

Expecting to find the perfect antivirus software is more like science fiction, and no antivirus software can be expected to provide accurate scan results every time – chances of false positives or negatives are always there.

So have a degree of trust in them, but also verify and be alert to the potential of false positives and false negatives.


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Kuntal Chakraborty
Technology Writer

Kuntal Chakraborty is an Information Technology Engineer by profession and education and the founder of Philarity.com. He has rich technical expertise working as a Systems Engineer and Network Engineer at Siemens and Atos. Kuntal has also worked in Artificial Intelligence (AI) and Machine Learning (ML) domains in different roles. Besides, he has a deep interest in Cyber security and published a few articles on it in some international publications. He has also created and successfully published some Alexa skills as a part of Amazon Alexa crowd developer community.