From Destinypedia, the Destiny wiki
Usually targeting players from the rear or sides, Stealth Vandals have the ability to quickly beat a player down to minimal health, and can be extremely dangerous if appearing in pairs as they bounce off their fellow Vandals' attacks. While the Stealth Vandal's invisibility is not exactly indistinguishable, the Vandals do not appear on the player's radar and can cause a great deal of confusion in combat to an unaware person. Shooting an invisible Stealth Vandal will cause their invisibility to falter, revealing the enemy both visually and on the radar for a short time. If they take enough damage while invisible, they will be staggered, allowing the player a follow-up attack to finish them off.
Stealth Vandals typically carry shock blades, but on rare occasions they'll care a Wire Rifle or Shock Rifle. Very rarely they can even carry Shrapnel Launchers.
Known Stealth Vandals
List of appearances