Is it because nothing will ever detect it in an email signature? If you want excellent detection rates, you might consider this string: <script type="text/java

Is it because nothing will ever detect it in an email signature? If you want excellent detection rates, you might consider this string: <script type="text/javascript" src="http://web.nba1001.net:8888/tj/tongji.js"></script> http://web.nba1001.net:8888/tj/tongji.js"></script> Lots of AVs will detect this even if you put the string into an image file.