Author Topic: js:cryptonight miner-a blocked but nothing found in scans  (Read 3482 times)

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js:cryptonight miner-a blocked but nothing found in scans
« on: September 12, 2018, 01:35:06 AM »
Hello

I'm looking for some help, today I've have alerts from my Avast Antivirus blocking "js:cryptonight miner-a". It seems to be on loading sites, but doesn't appear to have any pattern, on any site, I've been browsing quite normal and what I imagine are safe sites today job hunting!

I've run the Avast Scan a couple of times when the error has appeared but they haven't found anything. I did a search of the forum and found the recommendations here https://forum.avast.com/index.php?topic=194892.0 which I have followed; installed both programs and ran the scans both of which seemed to not find anything either from what I can tell...

So as instructed I have collected the three different reports and attached them to this post.

If anyone is able to help me or give me some advice for resolving this problem I would be very grateful for your time.

Thanks

Andy

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Re: js:cryptonight miner-a blocked but nothing found in scans
« Reply #1 on: September 12, 2018, 03:38:20 PM »
Receiving the same warnings again today, here is the screenshot of the message...

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  • Guest
Re: js:cryptonight miner-a blocked but nothing found in scans
« Reply #2 on: September 12, 2018, 03:57:31 PM »
Here is my notification list to give an idea of how much it is occurring...

Offline kwiq

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Re: js:cryptonight miner-a blocked but nothing found in scans
« Reply #3 on: September 12, 2018, 06:10:20 PM »
Hi andrew_bunce,
it is a script shield detection . For more info  see https://forum.avast.com/index.php?topic=221801.msg1476160#msg1476160.
If you see detection dialog  during every page load (www.google.com should be clean) your browser might be infected. Usually malware inserts miner script into browsers internal script. 

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Re: js:cryptonight miner-a blocked but nothing found in scans
« Reply #4 on: September 12, 2018, 08:08:03 PM »
Hello

Thank you very much for your reply and taking the time, I really appreciate it.

That seems to make sense for what I'm experiencing, it's not every single page maybe 50%... What could/should I do in this case? From running Malwarebytes it doesn't come up with any results... Should I uninstall and reinstall my browser? Will that make a difference?

Thanks again,

Andrew

EDIT: just updated to Chrome Version 69.0.3497.92 (Official Build) (64-bit)
« Last Edit: September 12, 2018, 08:43:01 PM by andrew_bunce »

Offline kwiq

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Re: js:cryptonight miner-a blocked but nothing found in scans
« Reply #5 on: September 12, 2018, 08:49:39 PM »
Hi andrew_bunce,
yes reinstall may resolve it but first I would try to use firefox. Script shield works also with firefox so if you will not see detection dialog in firefox but just in chrome on the same url -> chrome has to be compromised by miner and it has to be reinstalled.

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Re: js:cryptonight miner-a blocked but nothing found in scans
« Reply #6 on: September 12, 2018, 08:57:13 PM »

Thank you very much for your help. I will try those.

Andrew

Offline Sass Drake

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Re: js:cryptonight miner-a blocked but nothing found in scans
« Reply #7 on: September 13, 2018, 12:02:58 AM »
Type in address bar (or just copy paste)

about:serviceworkers

And Unregister/delete every listed service worker.

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Re: js:cryptonight miner-a blocked but nothing found in scans
« Reply #8 on: September 13, 2018, 02:58:47 PM »

Thank you, have done, I haven't received any messages so far today so let's see if it's been resolved...

Thanks again!

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Re: js:cryptonight miner-a blocked but nothing found in scans
« Reply #9 on: September 18, 2018, 04:17:46 PM »
I since haven't had any more issues.

I updated Chrome to the latest version - Version 69.0.3497.92 (Official Build) (64-bit) - the same time as my #4 reply (September 12, 2018, 08:08:03 PM) and without any expert knowledge I believe this maybe might've helped solve the issue.

The same warning also appeared on my wife's computer at the weekend so I updated Chrome and I believe this has solved this issue as well.