AT&T rbl block inquiry site

Monday, January 21st, 2008

First, I guess I should give a primer, what’s an RBL? RBL stands for Realtime Black List (or Realtime Block List depending on who you talk to.) The idea is there are machines that either 1) have no business DIRECTLY trying to deliver a mail message to a legitimate mail server or 2) are known [...]

Bellsouth/ AT&T mail problems

Wednesday, July 25th, 2007

I would dare say there are more than a couple people “out there” right now that are puzzled as to WHY some of their mail is bouncing back to them as being rejected. Right now I’m talking about Bellsouth / AT&T mail users…. it appears that this week AT&T is in the process of transitioning [...]

Why? (Why couldn’t AT&T make sure their mail servers weren’t using old dialup IPs that are blacklisted….)

Tuesday, July 24th, 2007

Why do I always wind up being the one to discover problems? …. Today in checking mail I found a mail that had bounced back from one of my clients that uses bellsouth… Now bellsouth has recently been bought by AT&T and it appeared as though the mail had been rejected because the mailserver trying [...]

More postfix spam blocking and Whitelisting….

Monday, January 22nd, 2007

I almost forgot to pass along a link to a more comprehensive detailing of postfix’s anti-uce controls…. here. Also, in the last article I briefly mentioned whitelisting. IF you intend to have several blacklists active it will pay to learn how to whitelist before you HAVE to. To do so, I simply created a text [...]

More postfix spam blocking….

Monday, January 22nd, 2007

Postfix has a NUMBER of tools for rejecting unwanted messages before they get in the door and waste your CPU time on deciding “hey this mail is spam”. Up until recently I’ve mostly used the relays.ordb.org check (which in the last couple months has now gone defunct.) When we started noticing problems with ordb.org’s responsiveness [...]

Watching out for MORE fake video codecs

Wednesday, October 18th, 2006

sunbelt blog has yet MORE fake codec sites to watch out for. All are bad and should be AVOIDED… details after the jump….    Send article as PDF   

More rogue security software

Tuesday, October 3rd, 2006

Wolves in sheeps clothing…. from Sunbelt blog…. Watch out for pestcapture and “friends” (using dlls from spysheriff). Thanks to sunbelt for keeping their eyes open on the threat of wolves in sheepdogs clothing…. It’s so frustrating having to explain to someone that the software they downloaded to solve their problems has become part of the [...]

Strange net problems with a Netgear FS608 switch

Tuesday, August 22nd, 2006

This was weird and now that the switch is replaced I haven’t been able to duplicate it, but let me explain. There was a netgear fs608 (8 port unmanaged) switch plugged into a linksys router (model number not noted.) The cable was straight (although the fs608 has support for link through straight or crossover cables.) [...]

Nasty Javascript attack possibilities

Friday, August 4th, 2006

There were demonstrations of some nasty javascript attacks at Black Hat as well (as if the wireless driver issues wasn’t a big enough problem…) Javascript is a powerful language and can be used for many things, but in these demonstrations, it was used to track recently visited sites (by the browser victim) and identify the [...]

Denyhosts as an added defence to ssh server

Wednesday, July 5th, 2006

A couple days ago I had a brief article on the vandals banging away at the door of my ssh server. Like I said, I’ve, at times, been fairly smug abou the futility of their actions, but…. the persistance concerns me. Let me be more specific, I keep a fairly tight ssh server setup (don’t [...]

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