Source: Interfax (Russian: Интерфакс) is a Russian non-governmental news agency based in Moscow. Carried by Reuters and reported by US Naval Institute News 8 Dec 2015:

http://www.reuters.com/article/us-mideast-crisis-russia-syria-idUSKBN0TR0TU20151208?feedType=RSS&feedName=worldNews#KSD9SVRjPVoMz92U.97

A later TV news item Tues evening 8 Dec reported an actual cruise-missile launch by this submarine against ISIS targets. Other reports indicate the sub is a KILO.