Trojan-PSW programs are designed to steal user account information such as logins and passwords from infected computers. PSW is an acronym of Password Stealing Ware.
When launched, a PSW Trojan searches system files which store a range of confidential data or the registry. If such data is found, the Trojan sends it to its “master.” Email, FTP, the web (including data in a request), or other methods may be used to transit the stolen data.
Some such Trojans also steal registration information for certain software programs.