CIS 4.1.150349.920 Virus Scan hangs

I am running CIS 4.1.150349.920 Virus Signature DB version 5080 and it hangs every time I do a virus scan. I have tried to uninstall and reinstall CIS about 2 times now but to no avail.

What I do see is that my PF Usage is extremely high when Comodo hangs and so is my Commit Charge. I look at the Task Manager and it shows me that cmdagent.exe had a peak memory usage of over 260 Mb but also had an excessive number of page faults.

I am running Windows XP SP3.


Hi Ashish,

Can you please try a Manual Scan with “Scan archives” disabled?
See if that finishes?


I will give that a shot. But just FYI - my scans were scheduled to run at 4 AM and they would normally finish around 6 AM. This (scan not finishing) has been happening for about two weeks. At first I suspected a virus but then I scanned using other software (BitDefender - which I have since uninstalled) and nothing came up.

What happens is that the virus scanner gets “stuck” at a file but the clock keeps going. Any attempt to stop the virus scan fails. I have to reboot each time this happens. Also, it is not the file it gets stuck at that is the issue: I have manually scanned the singleton file using Comodo and it comes up with nothing, and finishes.

I have seen other posts on this issue so I suspect it is not just me alone that is having this issue.

I will post the results of the manual scan (whether it finished or not) later today.

Thanks for your help and suggestion.



The virus scan still hangs. I had disabled the “Scan archive files” option and it still got stuck.


Should be an Update issue: disable the “update before scanning feature” on the AV tab.

No it is not an update issue. Like I said, if I scan one file, which also invokes the update, it is fine.

I am uninstalling CIS 4. Does not work for me at the moment.

I have the same problem. I am running a 3GB, 2.2Hz Windows 7 64bit machine. Every time I try a system scan, the virus checker runs for some time and then the machine suddenly goes incredibly slowly, or locks up completely. I’ve noticed that the file currently being scanned seems to always be somewhere in the User/Application Data folders. Not necessarily the same file. I’ve run partition checks and can find no faulty tracks or files. This started happening I believe after a clean update to 4.1.150349.920. The current virus signature is 5111, but I don’t think it matters which of the recent versions it is. It would seem to be some interaction problem with more than one program trying to access something or other, but that’s just a guess. When I can get Windows Task manager to give any info, there seems to be plenty of memory available still, and the CPU doesn’t seem to be much used either. That’s why I think there are two or more thinks waiting for the same thing.

Hi Oldster,

Can you use the context-menu scanner to narrow down the folder that could be causing it?
Test \Users first and after that go a folder deeper like \Users<UserID> etc to see if you can find where it freezes?

I’ve run it through twice with no hitch. My current thinking is that it’s either to do with the number of files being checked … I’ve noticed that the failure occurs after checking some 182000 files, or that there is interaction with Windows Live Mail which is usually running when my system scan starts, but not whilest doing the above check. Is it possible that Live Mail is changing the state of some files while Virus checker is running it’s check?

Maybe, can you try to run these scan’s also from a Scan profile?

There are several differences in scanning with the Context-Menu v.s. the build in scanner, maybe there is a clue, and also watching the CPU load and Memory usage with Tools like Process Explorer from Sysinternals might give a clue about High CPU load v.s. dropping memory usage etc

Hi achandra and Oldster,
In order to resolve this hang issue, i need to trouble shoot and need your co-operation.
I would like you to take following steps:

  1. Go to “Antivirus–>Scanner Settings” and de-select “Automatically update virus database before scanning” check box from
    “Real Time Scanning”, “Manual Scanning” and “Scheduled Scanning” tabs.

  2. Save as bases.cav on your computer
    SHA1: 824476c6c588be6e591da25d079227c19b1e6f51
    MD5: f1aa84dcb0b96b90b035b9d3f2525f64
    Size: 84.3 MB (88,463,191 bytes)

  3. Reboot in Safe-Mode

  4. Open explorer and go to
    “C:\Program files\comodo\comodo internet security\scanners”


    Type in following in “Start–>Run” and press Enter key:
    %ProgramFiles%/comodo/comodo internet security/scanners

  5. Rename existing bases.cav to bases.old and copy downloaded bases.cav

  6. Reboot your system in normal mode

  7. Now scan as you scanned earlier to cause CIS to hang.

Please check if it happens again and let me know. Depending on results, i will come up with next base to ZERO in the problem.


Note: The bases_0.cav is not production base and does not have same level of protection. It is intended only for this troubleshooting purpose.

Hi Umesh,

Thanks for your response. However, I have already uninstalled CIS and installed another anti virus. I cannot undertake this test at this time. However, if Oldster is willing to experiment, I will be very interested in the results.

I will keep following this thread.


I also have the same problem. I will try the method you provided and tell you the result (if my computer didn’t hang again).

Another question:
Is there an option to choose scan or not scan? Because the scan is so slow.

[attachment deleted by admin]

That’s a suggestion. You can ignore if you do not want to do a complete system re-scan.


It is sad to say my hard disk which install CIS was out of function. I try to rescue old data into new disk. I will try and tell you the result if my disk is back. :frowning:

Hi, Umesh

I try your method and the scan seemed quickly.

When I clicked “do it now”, the CIS also wanted to update the virus base.
So I did a manual “My Computer” scan which chose from the scan profile.

When CIS scaned “SINGLE” files, I can do other work simultaneously.
But when CIS scaned some “archive files”, the computer “hanged” awhile.
eg. hanged on c:\Windows\Help\fxsclnt.chm|FaxC…htm
During the hanged time, the mouse pointer fixed and could not move.

But I used the “Scan with COMODO Antivrus” in the right click menu to scan the same file, nothing happened. ???


I think you need to monitor the Memory v.s. CPU usage during archive scan, I have the same issue with the archive scan, it doesn’t seem to honor the 20MB limit inside archives.

When I scan a few .7z files that contain highly compressed files that are uncompressed 100MB registry exports I have a huge increase of Memory usage with 100% CPU usage to a point that the memory manager kicks in and drops the CPU to 0% then the memory stays high for like 10 minutes and after that drops back to normal <100MB then CIS seems to continue scanning.

Can you download process explorer from Microsoft here:

And monitor cmdagent.exe CPU vs Memory usage? (don’t use context-menu scan in this case).

On other thing you can try to determine if your having the same issue is disabling the archive scan for manual scans see how much that speeds up the scan.

You are right.

Now I use normal base to do full computer scan, I use Task Manager to monitor the CPU and Memory Usage of cmdagent.exe.

When it scan archive files, the CPU usage is always large than 79% and the memory usage is more than 60MB.

If the CPU usage is approached 100% or the memory usage is approached 100MB, the whole sytem will slow down.

Can you try this and see how that goes?