PSWBugbear.B is a Password stealer type Trojan that is dropped in computers by a dangerous worm called Bugbear.B.
It is very easy to become infected by this worm, as it is automatically activated when the message is viewed through Outlook’s Preview Pane. It does this by exploiting a vulnerability in Internet Explorer (versions 5.01 and 5.5), which allow e-mail attachments to be automatically run. This vulnerability exploit is known as Exploit/iFrame.
PSWBugbear.B logs the keystrokes entered in the affected computer in a file. By doing this, hackers that accessed this file would be able to obtain confidential data such as passwords for accessing certain Internet services, bank accounts, etc. The keylogger information is sent when the data saved exceeds 25,000 bytes or every two hours.
It also sends out a file containing a copy of the cached passwords of the dial-up connection to networks to a certain list of e-mail addresses. It does this if the default e-mail address of the victim computer, which it obtains from the Windows Registry, belongs to one of the domains in its list. This list mainly includes domains belonging to financial entities. The addresses it sends the cached passwords to are the following:
firstname.lastname@example.org, email@example.com, firstname.lastname@example.org, email@example.com, firstname.lastname@example.org, email@example.com, firstname.lastname@example.org, email@example.com, firstname.lastname@example.org and email@example.com.