Incidents
Re: Re: Compromised Windows Server Jun 06 2006 03:15AM
wnorth verizon net
>Some viruses use random filenames. If you've deleted them then there's
>no way to tell for sure what they were - if you do have them, send the
>files to http://www.virustotal.com/ for a diagnosis - though I would
>still re-install the box.

I don't agree with re-installing the box, that's a drastic measure, especially if it is a mission critical system.

I would do the following:

1. Make sure all critical patches have been applied and reboot the system.
2. Make sure you have the latest anti-virus client.

The first item, upon reboot if the virus/kit is self producing it will create new DLL's and execute the process again, if this happens I would suggest using something like find-n-fix (or some other variant program...some commercial products offer this) to explore your system and registry for files that are not readable during normal boot, or potentially have been written to the registry to initialize at boot, which could potentially recreate executables, thus rendering your system as it was.

The second item is just good practice.

Since it looks to be a virus, self-propagating (in that it is scanning other systems for RPC and SMB Transport) typically patching and updating anti-virus sigs after removal should do the trick, if it hasn't embedded itself in your registry, in which case a reg scan for items that start on boot should showup.

I've seen hundreds of systems affected, the brash (but typically most effective) approach is to re-image, but that doesn't always help to explain the nature of the problem or how they infected you, especially if you want to make sure you know how to remove it later.

Does anyone else have access to the system? Did you see if it was trying to transfer data when it was scanning? I'd be curious to see what it was trying to do...sounds very similar to mblast or something like it.

Was it scanning VLAN's sequentially including rfc1918 addrs?

Just some thoughts, and yes I have had to rebuild systems that were so infected the ROI on cleanup just wasn't there versus a brand new reinstall.

-Wes

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