How do I find out where a file in the browser cache came from (getting virus alert on a file in the cache)

Post by **thosrtanner** » 2026-07-09, 20:30

I think this is probably the best place to put this. Apologies if not. Anyway, microsoft defender has decided to flag a file in the browser cache is a possible virus (categorizing it as Trojan:JS/Redirector.PGRE!MTB) and quarantine it. I keep getting this message which is a little worrying, and it's the SAME file location every time. I'm not browsing anywhere different than I have been so I don't know whether this is a false alarm or whether a site I visit has got an infection.

But as I don't know what the file is actually called, I'm a little stuck.

Is there anything that can link a file in the cache to where it was fetched from?

Thanks

Post by **moonbat** » 2026-07-09, 22:20

Antiviruses are retarded. Create an exclusion in Defender for your profile and clear your cache.

ron_1 · Post by **ron_1** » 2026-07-09, 22:28

thosrtanner wrote: ↑
2026-07-09, 20:30
But as I don't know what the file is actually called, I'm a little stuck.

You're saying Defender doesn't tell you the name of the file it's flagging?

adoxa · Post by **adoxa** » 2026-07-10, 00:22

ron_1 wrote: ↑
2026-07-09, 22:28
You're saying Defender doesn't tell you the name of the file it's flagging?

No, the name of the file doesn't indicate what it caches. I had a similar problem a while ago (different type, though, I think might mine was just a heuristic), which I think was an old AdsBypasser Greasemonkey script. I think you'd have to actually look in the file to see what the URL is.

Post by **thosrtanner** » 2026-07-10, 06:15

So I've read a page with a virus and it's in my cache and it's quite safe? Really? Because the cache basically is the store of a web resource which could get run. I think that's very unsafe advice.

Post by **thosrtanner** » 2026-07-10, 06:16

it tells me the name of the file alright, and it's the same every time. But I'd like to know where it came from.

Post by **Moonchild** » 2026-07-10, 06:44

About:cache is your interface within the browser where you can query metadata. Not sure if a "reverse" search from the generated file name is possible though (not at the pc at the moment so can't check)

Post by **thosrtanner** » 2026-07-10, 07:42

It lists all the cache entries but not the filename as far as I can see.

Post by **Moonchild** » 2026-07-10, 09:25

OK, inspect the file in question in a file viewer near the end of the cache entry file should be the URL and other meta data.

Post by **thosrtanner** » 2026-07-10, 17:32

Well, that was interesting. It was a news feed for a comic that hadn't updated for a couple of years. it is now serving something very odd. It didn't make much sense as a feed as it wasn't valid xml, so safe enough from my point of view, but removed the news feed.

Bilbo47 · Post by **Bilbo47** » 2026-07-14, 18:35

thosrtanner wrote: ↑
2026-07-10, 17:32
It was a news feed ... that hadn't updated for a couple of years. it is now serving [not] valid xml

Apparently the probers took a previously-trusted route into machines around the world and attempted to break parsers, thereby learning new ingress vectors. Similar to supply-chain attacks, where repositories are primed with malware.

Pale Moon forum

How do I find out where a file in the browser cache came from (getting virus alert on a file in the cache)

How do I find out where a file in the browser cache came from (getting virus alert on a file in the cache)

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Re: How do I find out where a file in the browser cache came from (getting virus alert on a file in the cache)

Re: How do I find out where a file in the browser cache came from (getting virus alert on a file in the cache)

Re: How do I find out where a file in the browser cache came from (getting virus alert on a file in the cache)

Re: How do I find out where a file in the browser cache came from (getting virus alert on a file in the cache)

Re: How do I find out where a file in the browser cache came from (getting virus alert on a file in the cache)

Re: How do I find out where a file in the browser cache came from (getting virus alert on a file in the cache)

Re: How do I find out where a file in the browser cache came from (getting virus alert on a file in the cache)

Re: How do I find out where a file in the browser cache came from (getting virus alert on a file in the cache)

Re: How do I find out where a file in the browser cache came from (getting virus alert on a file in the cache)