see here :
http://www.quantenblog.net/security/virus-scanner-bypass
"From time to time a vulnerability is found in a virus scanner that allows an attacker to disguise malicious content so that the scanner won't detect it but the virus is still fully functional. Much rarer are discoveries of new attack classes that are able to blindfold not one but many virus scanners..."
clamav 0.88.6 vulnerable.
http://www.quantenblog.net/security/virus-scanner-bypass
"From time to time a vulnerability is found in a virus scanner that allows an attacker to disguise malicious content so that the scanner won't detect it but the virus is still fully functional. Much rarer are discoveries of new attack classes that are able to blindfold not one but many virus scanners..."
clamav 0.88.6 vulnerable.