ISIS militants have begun deploying aerial mines made of condoms and small packages of explosives, according to a report from Russia Insider, a Pro-Russian volunteer media outlet. The prophylactics are filled with a lighter-than-air gas and floated into the sky near Idlib, Syria.
There's speculation that the bombs are actually being deployed by other militant groups. Popular Science pointed out that Idlib is controlled by the al-Nusra Front, not ISIS. Rebel factions fighting against Assad like al-Nusra have been the primary target of Russia's bombing campaign in the area and it may be them resorting to extreme measures to try and get out from under the constant airstrikes.
The mines would be largely ineffective against the jets that conduct most of the attacks since the bombers fly at such a high altitude. They may have better luck against Russian helicopters that fly close to the ground, but it's still a desperate action that's unlikely to be successful. Protection from STDs and protection from aerial attacks don't normally require the same equipment.