[morgano]

I've had this bot crawl also, every bot appears to be viewing an attachment. I guess it's a bot net trying to exploit forums via attachments. I guess it crawls the net. The largest number I had was 200, it starts high and dies off after an hour or so. It takes around 24 hours for the entire botnet to clear the server. I've had the same botnet appear back on the forum multiple times in smaller numbers. Everytime they were doing to the same activity of viewing attachments. Fortunately I haven't seen them for a few weeks and they never disrupted my server whilst they visited.

If your interested all the IPs were dynamic "dynamic.saudi.net" with alternating IP addresses once resolved. Nothing much I could do but ignore them at the time.