AvAgent.exe dies with Visual C++ "runtime error"

I opened a support ticket immediately with this one, because it’s a pretty urgent problem (seems to have caused our primary server in a business LAN to need an ungraceful shutdown during business hours, with potential data loss), but I haven’t received any reply from support in over 24 hours so I will post here also:

AMS is installed on a computer running Windows Server 2003 R2 SP1, Enterprise Edition, call it server A. The managed client on server A stopped communicating with AMS shortly after its nightly scheduled on-demand scan started, two nights ago. Meanwhile the managed client on server B (Windows Server 2003 SP1, Standard Edition), which is our “primary” domain controller and main application & file server, also stopped communicating with AMS, at about the same time.

On both machines, a logged-in console session was active and when we connected to it we found the following pop-up, labeled “Microsoft Visual C++ Runtime Library”:


Runtime Error!

Program: D:\Program Files\Alwil Software\Avast4\AvastAgent.exe

This application has requested the Runtime to terminate it in an unusual way. Please contact the application’s support team for more information.

[OK]

We clicked “OK” on server B and then manually instructed the managed client on that server to do an iAVS update. At this point the console started to become unresponsive.

Meanwhile several of our XP machines (I think 5 of them) also were having trouble. Like the servers, they had not contacted the AMS since shortly after their nightly on-demand scan started. We could not even log into these computers. The log-in process would start and then appear to hang at a blue screen (not blue-screen-of-death, just the default background blue of XP), or in some cases they would “hang” after the user’s desktop wallpaper appeared.

In all cases we could use pslist from sysinternals to remotely view the processes running on the XP clients, and no process seemed to be running abnormally. CPU would bounce between 99% and 100% idle, and as far as we could tell, no process was eating huge amounts of memory. I assume that AvAgent.exe hit the runtime error on the XP machines also, because these machines were not communicating with AMS. But we can’t know for sure because there was no active session logged-in to these machines, that we could just connect to. And the runtime error does not seem to leave any trace of itself in the Windows event logs, or in avast’s internal logs, either on the clients or on the AMS.

Meanwhile our 20 other XP machines were doing just fine. Eventually people started having trouble opening shared files on server B, though, and since we couldn’t get into its console we had to force it to shut down by physically powering it off. The windows “shutdown” tool did not work from a remote computer. :-\

Just wondering if anyone else has seen this or if anyone at Avast can recommend troubleshooting tips. The AvAgent.exe on server A is still in the state we found it in yesterday morning, with the Runtime error popped-up on the screen. I used userdump.exe to take a process dump (which seems to have failed, at least partially) and I put a zipped copy of the dump in ftp.avast.com/incoming. The file is named after the support request I opened yesterday. I’m happy to do any other debugging/troubleshooting that’s required.

We are running ADNM 4.7.608 and AMS v4.7. The managed client installed on the two servers is 4.7.700.0, but the client installed on most of the XP machines that were having trouble is 4.7.599.0 (one of them is running 4.7.700.0, though).

Thanks in advance for any help.

If anyone from ALWIL is reading this, can you please advise me as to what else I can do to determine the cause of this problem? I still have virus-scans turned off on our servers because I cannot afford to have the servers “lock up” again during business hours. The people working on my support ticket seem want to clear the error state and update everything to see if the problem goes away. But if I do that, and the problem does go away, I won’t have much confidence that the problem is actually fixed – perhaps it just wasn’t triggered again right away. That’s why I want to know what happened in the first place.

Thanks, Ben

I’m not sure if it will work, but what about making a dump?
To create the dump, download and run http://public.avast.com/~vlk/hangrep.exe . In the list of processes select D:\Program Files\Alwil Software\Avast4\AvastAgent.exe and use the Save button. This generates a file which you can either send to his email address vlk (at) avast.com (if it’s smaller than e.g. 1 MB, ZIPed), or upload to ftp://ftp.avast.com/incoming

The command-line version http://public.avast.com/~vlk/userdump.exe . The syntax is
userdump.exe “D:\Program Files\Alwil Software\Avast4\AvastAgent.exe” c:\AvastAgent.dmp
(producing dump file in the root of C:\ drive).

Also, check the folder \data\log
Are there any files called unpXXXX there (where XXXX is a random number)?
If so, send them to vlk (at) avast.com
They may contain more information about the problem (maybe a link to this thread).

Hi bslorence,

sorry for not replying earlier - I must have somehow missed your original post.
The issue was caused by one of the VPS updates (namelly, 0761-0). While scanning some specially formatted files, it was causing EXACTLY the problem you’re describing.

The issue was addressed in the following update (0761-1, released about 8 hours later) but still, during the 8 hours, the buggy VPS caused quite a lot of problems… >:( [to be honest, it caused problems on our own email server :-

I apologize for this incident; we’ll make sure it won’t happen again (actually, this was the first time in the history of avast when a VPS update was causing problems like this).

Cheers
Vlk

After Vlk’s answer, mine is no use. Forget it.
This is what makes me a proud avast user: they recognize (acknowledge) errors and bugs, you can trust that they work seriously. Not all the companies have this policy.

Vlk, no problem, I got the same response through support.avast.com. Thanks! -Ben