Author Topic: Avast U3 Edition  (Read 4317 times)

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JerryM

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Avast U3 Edition
« on: June 26, 2007, 03:33:50 AM »
Will the U3 edition of Avast on a flash drive cause conflicts with a resident AV on the computer that is plugged into? It appears that while it is primarily intended to protect the programs on the U3 flash drive, it can also be used to scan the host computer.
From the Avast site,
"Last, but not least, it can also scan for viruses and other types of malware hidden in Alternate data streams on NTFS volumes of the host machine."

I don't know anything about a U3 flash drive, except that I bought one to place Firefox portable on. Avast U3 is on the drive, but I wonder about potential conflicts with the resident AV.

Thanks,
Jerry

Offline igor

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Re: Avast U3 Edition
« Reply #1 on: July 01, 2007, 06:44:28 PM »
I think it shouldn't conflict, at least not on the driver level (which might cause the computer to freeze, for example). avast! U3 Edition doesn't use any drivers, so this shouldn't be a problem.
If an infected file is written on the device, it might happen that both AVs react... but I think an full-featured (resident) AV would react first, blocking the whole operation (so I assume there wouldn't be any conflict here either).

Offline RejZoR

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Re: Avast U3 Edition
« Reply #2 on: July 01, 2007, 07:22:09 PM »
That about two resident AVs locking up on infected files is a myth. It's always some AV that takes over first and other one won't even know what happened.
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JerryM

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Re: Avast U3 Edition
« Reply #3 on: July 01, 2007, 09:30:29 PM »
Thanks to both of you for the replies.
Regards,
Jerry

Offline igor

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Re: Avast U3 Edition
« Reply #4 on: July 01, 2007, 10:12:04 PM »
That about two resident AVs locking up on infected files is a myth. It's always some AV that takes over first and other one won't even know what happened.

I don't think it's a myth. Vlk wrote about it here.
I think he posted a more detailed explanation here, but I can't find it right now.

I think that locking of the scanner shouldn't happen here (because of different levels the 2 antiviruses most likely work on)... but thinking about it, if there's a packed malicious file that avast! (and also the other antivirus) detects only when unpacked, the last scenario might happen; avast! unpacks the file to a temporary file, this temporary file gets detected by the 2nd AV, possibly forcibly deleted... so avast! doesn't see the infection and lets the packed file be copied to the U3 drive, undetected - which wouldn't happen if the 2nd AV didn't interfere.