Hotlan Trojan defeats captcha
A new Trojan horse that sends spam through Hotmail and Yahoo email accounts has antivirus companies worried that the commonly used "captcha" system, used to prove new members are real people, may have been compromised. Captcha systems typically use a selection of alphanumeric characters that have been distorted and presented in a graphic with other elements designed to confuse character-recognition software. The idea is that, as only a person can read it and type in the correct sequence, spam bots and other malware can be stopped from automatically setting up accounts. The new threat was highlighted on Thursday by BitDefender Labs, which has dubbed it Trojan.Spammer.HotLan.A.
McAfee - Spam-HotLan (DAT 5070 offers detection/protection)
This is a spam trojan which downloads a remote script to log into various free webmail accounts, in order to send spam. The script then tries to contact a second site, which contains details about the spam emails to send. At the time of writing, this second site returned nothing. This trojan does not install itself to the local system - once a system is rebooted, it will not restart itself.
BitDefender - Trojan.Spammer.HotLan.A
There aren't any obvious symptoms of this malware, except increased internet activity.