|by Flemming Funch|
I've again turned on that trackbacks show here, as I'm more confident that spammers can be thwarted fairly easily. Basically I've installed mod_security, an Apache module which makes it quite easy to filter all web accesses, form postings and so forth, and catch when various keywords are used, in addition to catching various behaviors that are likely to be hacking attempts, like trying to access unauthorized directories, etc.
There's something arriving several times per minute. Most often just a robot accessing some blog page and including a fake referral URL, pretending there's a link on some gambling site to that page. Which there isn't. But also attempted comment postings and trackbacks. The latter having been the most problematic, as I have them show up prominently as comments in the articles. So I had that turned off for a while.
The drawback to keyword filtering, however, is that I have to manually configure a list of keywords that trigger the alarm. I'm after the ones that appear in URLs and that I'm pretty sure have no business here. Viagra, poker, incest, texas hold-em - that kind of thing. And I'll have to add new ones when they're used. I try to limit the filter to comment and trackback postings and to referrer URLs. But it is quite possible that this will block some legitimate uses of those words. So far it seems to work pretty well.