Windows Defender Ties Paid Antivirus Software in Malware Tests

Paying for antivirus software has long been considered a necessity, but a recent study by independent labs has thrown this assumption into question. Between February and May 2026, AV-Comparatives ran 400 real-world attacks on various antivirus products, including Windows Defender.

The results showed that Microsoft Defender and Kaspersky were tied at the top with a 99.8% success rate, followed closely by Bitdefender with a 99.5% rate. However, what's more significant is that Defender recorded no false positives, while the paid options had five.

This finding suggests that Defender may be just as effective as its paid counterparts in protecting against malware, but at no cost to the user. The test also highlighted Microsoft Defender's reliance on cloud-based protection, which allows it to tap into Microsoft's live reputation and intelligence.

However, a closer look at the data reveals that Defender's local engine has a lower success rate when compared to other products. This raises questions about what exactly users are paying for with their antivirus subscriptions.