Contacting ClamAV community might be your best bet, if you are really worried about viruses on Maemo. http://www.clamav.net/ (AFIK) ClamAV is the only open source anti-virus software for *NIX based systems. I very seriously doubt that any of the commercial vendors would be interested about making Maemo port, or that any developers here would be interested about wasting their time and effort for something as trivial as this.