locked file

[alpha1]

when scan report opens after on-demand scan,there's a long list of errors: error,locked file.
my question is,are these files getting scanned or not?

[DavidR]

If a file is locked by another process or password protected, etc. then it isn't being scanned. Unlike many other AVs avast will report files that haven't been scanned and the reason why.

Files that can't be scanned are just that, not an indication they are suspicious/infected, just unable to be scanned, but worthy of investigation.

Many programs (usually security based ones) password protect their files for legitimate reasons such as AdAware and Spybot Search & Destroy, there are others (and avast doesn't know the password or have any way of using it even if it did know it).

When you run scans with the above programs and you delete harmful entries that they detect, a copy is kept (in quarantine/restore/backup) in case you need to reverse what you did. These are usually password protected, you should do some housekeeping and delete old backup/recovery/quarantine entries (older than two weeks or so), this will reduce the numbers of files that can't be scanned.

By examining 1) the reason given by avast! for not being able to scan the files, 2) the location of the files, you can get an idea of what program they relate to. You may need to expand the column headings to see all the text.

If you can give some examples of those file names, the locations and reason given why it can't be scanned might help us further ?

[alpha1]

thanks dave,i'll run another scan and investigate further,i'll  check back for help if needed.
btw,i only have malwarebytes on-demand,and my system is always clean,so no quarantined items.
also,i haven't noticed locked file errors on boot scans.

[DavidR]

You're welcome.

[alpha1]

i did another scan,it seems that all of the "password protected archives" are either items in recycle bin or files in k-lite codec pack,except 1 file which was neither,i think it was a video file or something.

any thoughts?

[Lisandro]

Don't worry.
Clean the recycle bin.
Locked files are just files in use, not infected. avast is just reporting them.
Run a boot time scanning.

[DavidR]

i did another scan,it seems that all of the "password protected archives" are either items in recycle bin or files in k-lite codec pack,except 1 file which was neither,i think it was a video file or something.

any thoughts?

Aside from clearing the recycle bin there is little else to do as it looks like k-lite protecting some of its codec files.

It does depend on what files are selected to be scanned, if you have selected All packers then you are going to come across more password protected archives. I never select archive files for scanning (other than the 4 selected by default) as they are inert files.

You need to extract the files from the archive and run any executable that was extracted before it is an immediate risk. Before that is likely to happen the file system shield will have scanned it.

[alpha1]

yes, thank u,ur right,i have selected all packers,which probably is the reason.

[alpha1]

If a file is locked by another process or password protected, etc. then it isn't being scanned. Unlike many other AVs avast will report files that haven't been scanned and the reason why.

Files that can't be scanned are just that, not an indication they are suspicious/infected, just unable to be scanned, but worthy of investigation.

Many programs (usually security based ones) password protect their files for legitimate reasons such as AdAware and Spybot Search & Destroy, there are others (and avast doesn't know the password or have any way of using it even if it did know it)

this raises questions regarding scan effectiveness (avast or others) when they cant scan password protected files a)what about password protected folders? b)infected password protected
files? c)viruses,malware etc that protects itself with password or something?

[DavidR]

yes, thank u,ur right,i have selected all packers,which probably is the reason.

Yes that is almost certainly the reason.

Not sure what you were doing in just quoting my earlier post, without any additional comments ?

[alpha1]

Not sure what you were doing in just quoting my earlier post, without any additional comments ?

sorry about that,first time quoting,i did add a post 2 that quote.

[DavidR]

<snip>
this raises questions regarding scan effectiveness (avast or others) when they cant scan password protected files a)what about password protected folders? b)infected password protected
files? c)viruses,malware etc that protects itself with password or something?

No it doesn't, as this is a password protected archive, which in its archive state is inert.

It has to be unpacked and when that happens the contents are outside of the password protected archive and can be scanned.

Before an executable file is run avast scans it, so there are a further two stages when the contents aren't protected and can be scanned. That is the point of on-access, resident anti-viruses, if there is access to the file then that triggers a scan by the file system shield.

Can you imagine how long a scan would take, if you had archives scanned if your AV tried a brute force password cracking every time it came across one, on the average PC forever.

[Lisandro]

this raises questions regarding scan effectiveness (avast or others) when they cant scan password protected files a)what about password protected folders? b)infected password protected
files? c)viruses,malware etc that protects itself with password or something?

No, not at all. Protected archive files are inert by nature.

[alpha1]

i guess ur right,but how do u know i have an average pc  ?

[Nesivos]

Another option is to select All Packers the first time you run a specific type of Scan.

If there are locked or password protected files then you can decide if you think are safe or not. 

If you think that they are safe then you can exclude those files from that Scan in the future.