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Microsoft Defender Antivirus found Trojan:Script/Wacatac.B!ml in langpack-en-US@firefox.Mozilla.org.xpi

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  • Last reply by SuMo Bot

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I recently had Firefox auto update the version of Firefox on my windows computer I have for personal use. Within 48 hours or so, Microsoft defender gave me the following notification in the image below, also mentioned in the title.

A little research has had mixed results on Reddit. Anyway, I am not directly looking for advice here on securing my device. Rather, I am wondering if there is any chance this could be a problem on the Firefox end, perhaps an issued caused by the recent update? Thanks.

I recently had Firefox auto update the version of Firefox on my windows computer I have for personal use. Within 48 hours or so, Microsoft defender gave me the following notification in the image below, also mentioned in the title. A little research has had mixed results on Reddit. Anyway, I am not directly looking for advice here on securing my device. Rather, I am wondering if there is any chance this could be a problem on the Firefox end, perhaps an issued caused by the recent update? Thanks.

All Replies (3)

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That is a Firefox language pack that adds string translations for the user interface and doesn't have active code, so this is likely a false positive.

Best is usually not to let your AV software scan the profile folder (i.e. make an exception) as this can lead to data loss.

If seen another thread about this.

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Hi, thanks. A little more research has me also concluding that this is a false positive. Thanks for sharing the link to the other post, my file was also found in a sub-directory of “profiles”. Any chance you know why this would have been installed, with my installed version of Firefox being the “(x64 en-US)” version per the photo? Thanks, and I know there may be no obvious answer.

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