Bizarre comment spam.

One of my sites employs a comment/user submission system.

Up until now I have never had the need to have auto publish set to off, in fact the amount of posts I have to remove is about 1 in every 100. I use a captcha system which has worked pretty well up until now.

Lately I have begun to get a barrage of automated spam, from a range of different IP ranges. I assumed that this was just due to the spammers working around the captcha I installed (a publicly available one) however the content of ALL the comments resembles (this is a C&P):

Title: slzsnbbq
Text: bdufoswz http://itneqyaj.com brvvxnsh clpwwfwq gckphlux barhvkjv

The domains are just word jumbles and do not resolve and the keywords are the same...

What the?

Sounds like you have been attacked by a defective spambot.

Very possibly. Yet still they come...

I started getting some weirder comment spam yesterday. No links in the post, and vague, if real language. But the user URL was still a spam site.

Manual review is quite necessary.

Hmm that is weird, perhaps someone is testing a new spam bot and just put in some random strings for testing in order to see what could get past.
________
Squirting hardcore

I even had one that quoted and replied to previous real comments, but it was all vague

"No you are wrong."

"I agree"