Windows 2003/XP/2000/NT

Dialer.HCO is a dialer type malware. Dialers usually try to establish phone connections with high rate numbers, significantly increasing the phone bill of the affected user.

Dialer.HCO affects computers that use a modem to connect to the Internet, as the virus modifies the Dial-up network access settings. It changes the telephone number provided by the ISP (Internet Service Provider), which is a local-rate number, to a high-rate number.

Dialer.HCO does not spread automatically using its own means. It needs an attacking user's intervention in order to reach the affected computer. The means of transmission used include, among others, floppy disks, CD-ROMs, email messages with attached files, Internet downloads, FTP, IRC channels, peer-to-peer (P2P) file sharing networks, etc.

Dialer.HCO is easy to recognize, as it shows the following symptoms:

• It changes the homepage of Internet Explorer.
• It creates shortcuts in the Windows Desktop.