[clamav-users] Clamav Definitions vs. Devel-Clamav Definitions

[Peter Folk]

Hello,

running into a weird issue here... our web host has run a clamav scan on
our VPS server, and found 1 infected PHP file, infected with
SL-PHP-BACKDOOR-GENERIC.

The clamav engine version used in the scan done by the web host was:
devel-clamav-0.99-beta1-632-g8a582c7 (that's what the log file says)

Now, I can't find that engine version anywhere on the web.

But, we installed the latest, stable clamav 0.9.4 on the CentOS hosting
box, updated definitions to latest via freshclam (it says Engine version:
0.99.4) and ran a clamav scan on the exact same files as our web host did.

clamscan does NOT find any infected files.

Can anybody explain why these definitions/engine versions are different.
and why does devel-clamav engine find infected files and latest clamav
engine does not.... ?

most importantly: how can I install and use the devel-clamav engine ??

Thanks.

Peter