If this report is accurate, then the attackers were likely members of, or sympathizers with Daesh (ISIS, ISIL), which holds territory in Syria and Iraq, and against which France began flying missions in September. Another possible culprit is core al-Qaeda or one of its affiliates, such as the Support Front (al-Jabha al-Nusra) in Syria. The Support Front does not, however, have territory in Iraq, and France has not specifically targeted it in the west of Syria, as opposed to hitting ISIL in the east.
When I was in France in mid-October, I was told by a former diplomat that President Hollande had decided to begin flying missions against ISIL in Raqqa, Syria, last September because French intelligence had learned that ISIL was planning to hit France.........This operation may, then, have been planned even before France was militarily involved in the campaign against ISIL in Syria, and the terrorists’ assertion that it was revenge for that intervention of the past two months has things backward."
P.S. See also http://www.aljazeera.com/news/2015/11/paris-attack-affect-syria-policy-151114062610843.html