How do I get rid of a permanent guest?

I just finished going through all the security patches and a few other things to recover from a hack and my website now seems to be doing okay.

However, I have a permanet guest who shows up whenever I check who's online in my admin area. When the tme since last clicked clock reaches 23:59:59 for how long they've been viewing the site it just turns over to 0:0:0 and then ticks away until it needs to turn over again. Here's the information taken from who's online:

17:38:05
ID: 0
Name: ¥Guest
IP address: 66.142.244.33
Session: 21:05:55
Entry Time: 21:05:55
Time Since Clicked: 17:38:05 ago
Session ID: 380a065fa1682503bdd8e1840e0ccb25
Host: mich-66-142-244-33.michaels.com
User Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; GTB6; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)
last URL visited: /

Please can you help me knock this guest off my website as I do not think it is a real guest. I've blocked the IP address and the hosting domain in my cPanel and that didn't do it.

Kathy

I use version 1.3.7 and have numerous addons
http://www/katzgardengloves.com

mich-66-142-244-33.michaels.com actually resolves to a website...... do you have a content sharing or affiliation with michaels.com?

Not a spoof... valid US IP from Plano, TX

~Melanie

If michaels.com is connected to the chain art supply store, then I don't have any kind of relationship with it. In fact I don't have ties to very many other websites. Certainly not one that keeps an open page on a computer to my main page. The company that supplies my products has me listed but they don't have ties to Michaels either.

It just seems wrong to have a guest on all the time. Am I crazy to be concerned about this? Especially since I just finished recovering from a hack.

Kathy