I’ve been using Windows Defender for a few years now without issue. The last few days, it’s been going crazy, running scans every few minutes while I’m working (it’s actually quiet while idle, but ramps up as soon as I start working). I thought it was because I had a Firefox session with 50+ tabs open for a few days, but it continued to act funny even after closing the file. It seems to activate any time I open up an Office file (yes, it’s a legal copy) and the scans will take a 5-15 minutes (they happen like 10 times a day). It doesn’t matter if the file is local or downloaded. These scans don’t show up as scans in the Windows Defender log though, which is odd. Actual quick scans only take 30-40 seconds. These mystery scans are much longer.
I am using an ITX build so I immediately know it’s running as my fans start ramping up to keep the heat down (this is confirmed as soon as I open task manager). CPU usage isn’t crazy (10-20%) but it seems completely unnecessary (and the fan noise annoys me).
I’ve downloaded Kaspersky as a stopgap, but I don’t like bloated third party AVs. Any ideas on what could be causing Windows Defender to go crazy?
I ran a full Windows Defender (no issues when I run a manual scan), Malwarebytes, and Kaspersky scan, and all came back 100% clean (I’m a responsible user) except for a handful of corrupted MS Office cache files that Kaspersky found. I do a lot of work over Office Sharepoint, and it’s a total shitshow with files becoming corrupted all the time. Could that possibly be what is setting off Windows Defender? So far, Kaspersky doesn’t have the problem of scanning every few minutes (it’s been sitting quietly in the background, and my computer has been nice and quiet as a result).
For context, it’s a beefy system (5600X + 16 GB 3200Mhz RAM + 2 TB SATA SSD + 2 TB PCIe 4.0 NVMe)