That drive by was under my control. Back in maybe 2010 or so. At that moment I had Comodo firewall (custom rules set), Sandboxie (allow to start for all programs, connection to internet for mozilla and chrome only). I went to malwaredomain list (i think). I found an ,,adobe drive by". I went to that site. I had an alert of Sandboxie about ,,reader.exe wants to connect to internet"". The page was blank. I allowed connection. After i had a Comodo alert, i blocked connection. After PC restart i went to antimalware.ru (i wanted to see reaction of Sandboxie and Comodo to pdf file). I saw normal pdf file and... connection from adobe. I blocked connection, the pdf file was normal, i could see it. At that moment i understood that adobe connection can be blocked because in order to see a pdf file on line, adobe doesn't have to connect to the internet. Maybe adobe was looking for updates or wanted to send statistics. In real life i had only 1 drive by (Back in 2004). I had Windows 98 (sic). No antivirus. I was working for a small company. My desktop was attacked by zoophilian page ( I was looking for information about a German archaelogical culture and Voila). I cleaned my PC with norton symantec and Adaware free). After that i began to learn about PC security. Regards.