interesting that before Turkey/Russia conflict everybody knew and wasn't really bothered, ie. business as usual, that Sunnis in Middle East, primarily Saudis and Turkey, do aid ISIS. In particular, ISIS fights Kurds and Assad - thus doing Turkey's and Saudis' bidding (Saudis need Assad gone because he blocks the Saudi gas pipeline to Europe and this is one of the reasons why Russia has been supporting him all this time :). Turkey and Saudis are US allies, while the other side - Shia like Assad, Iran, Hezbollah - are enemies of US. Everything was going great until Russia moved in and pooped the party :)
Beside global goals, like making itself important again by actively supporting the anti-US side, one of the practical Russian interest is in breaking up the flow of really cheap oil - from ISIS to Turkey to Ukraine's Odessa refinery (thus also hitting Ukraine too. In 2014, amid Russia/Ukraine conflict, Russia stopped sending its oil to the refinery, and that huge refinery has since then found another, even bigger source of oil, from Turkey :). Like Russia, Ukraine is a very corrupt state (and Odessa governor is the former president of Georgia - Saakashvili - with deep "business" ties to Turkey from his time in Georgia. It is very interesting story in itself on who, why and how put him into governor chair of strategically important large region of another, completely unrelated, country :) so nobody is asking questions about the oil provenance there, and as result there is 2 stage "laundering" of final oil products - first dilution of ISIS oil into "legal" Turkey oil and passing the result through the refinery (plus selling a lot of that cheap oil and its refined products into "no much questions asked" markets of Eastern Europe like in particular Ukraine and Poland. You may have already heard about extremely cheap supposedly Saudi oil hitting market in Poland. That flow of cheap oil negatively affects ("dumping" is the keyword here) Russian oil sales into these next-door markets and thus hits Putin's regime where and when it really hurts, and thus all this "cold war" between Russia and Turkey, and i personally have no doubts about who attacked the Turkish Internet :)