Author Topic: Problems with scanning  (Read 3028 times)

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Offline amirali1928

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Problems with scanning
« on: August 10, 2008, 09:17:44 PM »
I am not a techie, and being a retired person I downloaded on 12 July 2008 the avast! version 4.8 Home. The current version on my computer is 4.8.1229. My computer is Dell Inspirone 1505 with Windows XP Media Center Edition, 60GB hard drive and 1GB RAM (Duo).
I have been having the following problems with avast!
1) My daughter, a medical student, has a lot of her research material on a 2GB flash memory. Recently, she took it to the hospital in order to exchange files with colleagues. Knowing that the hospital computers have many viruses, she asked me to scan it on my computer. The Simple User Interface does not list a flash stick in the removable media and therefore I scanned it via Start>My Computer>Scan Kingston:\. As expected, it threw up scores of viruses, mostly Win32:Virut and variables thereof like Win32:Trojan, Win32:Runonce, Win32:AgentH-H, etc. I moved them to Chest, as recommended. However, after the scanning was completed, we found to our horror that most of the files on the flash tube were no longer there. I ran the scan once again and saw during the process that the missing files were still there. They were now 'hidden', but they did not become visible even via Control Panel>Folder Options>View>Show Hidden Files & Folders. I checked it on another computer, which has an outdated AVG on it and all the files were visible and readable. What can I do to have these files visible and readable on my computer also?
2) Standard scan thru Simple User Interface ends up giving me a list of 93 files/folders with "Unable to scan ...." written against each one of them. In a small box on the top left is written 'Action'. When I click it, a drop-down menu lists 'Delete', 'Repair'-(greyed out', 'Move ....', 'Chest' - in bold font, and 'Scan'. Nothing happens when I click 'Scan'. I am afraid of pressing 'Chest' to avoid a similar situation as in case of the flash tube. What is the right action advisable for me?

Offline Lisandro

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Re: Problems with scanning
« Reply #1 on: August 12, 2008, 04:48:40 AM »
What can I do to have these files visible and readable on my computer also?
avast shouldn't mess with any file attributes or hide files...
I suggest you get really sure the USB drive is clean (maybe using on-line scanning on it).
Kaspersky (very good detection rates)
ESET NOD32
Trendmicro housecall
F-Secure
BitDefender (free removal of the malware)

2) Standard scan thru Simple User Interface ends up giving me a list of 93 files/folders with "Unable to scan ...." written against each one of them. In a small box on the top left is written 'Action'. When I click it, a drop-down menu lists 'Delete', 'Repair'-(greyed out', 'Move ....', 'Chest' - in bold font, and 'Scan'. Nothing happens when I click 'Scan'. I am afraid of pressing 'Chest' to avoid a similar situation as in case of the flash tube. What is the right action advisable for me?
Files that can't be scanned are just that, not an indication they are suspicious/infected, just unable to be scanned. Right now, do nothing. Maybe the on-line scanning reveals more.
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Offline olddog

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Re: Problems with scanning
« Reply #2 on: August 12, 2008, 12:09:19 PM »
amirali1928,

Regardless of whether you scanned you USB flash drive from the Avast "scan" in the Windows Explorer right click menu, or from the "Folders" scan in the Avast Simple User Interface, the result should have been that when it found a file with a virus, it should have put up the virus warning and offered you the choice of Move/Rename, Delete, Move to chest. If you selected Move to chest, it should have done just that, and the file on the USB drive should have been "deleted".

So if there were large numbers of files found on the USB flash drive with infections and these were moved to the Chest, when you next looked at what was on the USB drive, it should have contained only those items which were not infected, and in tests I have run using a USB 560MB flash drive (memory stick) with EICAR virus test files on it, thats exactly what occurred.

Now on the flash drive I used on my tests, the files "moved" to the Chest on the hard drive were no longer visible at all on the USB drive using Windows Explorer, nor did Avast show them at all on subsequent scans of the USB drive, so I don't know why you can see them greyed out.

On a normal hard drive, a simple delete doesn't really delete a file, but just alters the drive table so it is no longer visible. I am not sure whether avast uses a more secure wipe process to overwrite the data in the original infected file before it "deletes" it, but I believe even wipe processes are not always completely effective on USB flash drives because of an internal hardware feature implemented to stop sections of the flash memory from being excessively used, so perhaps the hardware in the particular flash drive you have is still allowing you (and avast) to see the drive table entry for the original files, greyed out and not able to be accessed - but that's still pretty odd.

A copy of the infected files should still be in the Chest, and you could restore them to the flash drive, but that would be most unwise as they would still be infected and without putting a noose around you neck and turning off avast, you still wouldn't be able to open them. Rescanning them with another antivirus scanner would perhaps give you an idea of whether any of the files nominated by Avast as infected were just false positives, but that is unlikely to be the case for such large numbers of files.
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Offline rogerfgay

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Re: Problems with scanning
« Reply #3 on: August 12, 2008, 11:37:26 PM »
I just installed Avast and am running my first thorough scan on a dual core intel machine (HP dv9000 series laptop). It's been running for about 2 hours so far and says it's scanned 8% of the files. I'm also running it on an older machine that's so far scanned 3% of the files in about 3 hours.

Offline amirali1928

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Re: Problems with scanning
« Reply #4 on: August 28, 2008, 08:12:07 PM »
I just installed Avast and am running my first thorough scan on a dual core intel machine (HP dv9000 series laptop). It's been running for about 2 hours so far and says it's scanned 8% of the files. I'm also running it on an older machine that's so far scanned 3% of the files in about 3 hours.

As mentioned in the problem I had posted for myself, I am not a techie and therefore not in a position to give a solution to the issue mentioned by you. The only thing I can give you is a comparison to show that scanning on your computer is very, very slow.
I have Windows XP Media Center Edition installed on a Dell Inspiron with Intel (R) Core (TM) 2 CPU 1.66GHz T5500, 60 GB Hard Disk, 1 GB RAM (Duo) and the latest version of avast!, which is 4.8.1229, Build Jul 2008. In my case, in the Simple User Interface, Test of Memory and Startup takes only a few seconds, and the scan a few days back of the total system, which then comprised 321745/6448 folders/files, with a size of 22.7 GB, took 00:28:06 Hours.

I am not familiar with the speed of HP dv9000 series but I am sure it would be comparable with Dell. Obviously, some expert may answer your well based concern but, in the meantime, please do scan your system with a good anti-virus (other than avast!) and a good anti-spyware. The names suggested to me thru this forum are: kaspersky, EET NOD32, Trendmicro housecall, Bitdefender, AVG8.0, etc. PandaActiveSecurity has also been spoken highly of by a friend although it does not seem to have worked on my computer so far.