Malgus personal Death Squadron fleet reached the Hoth system, following a chance discovery made by a Viper probe droid that was sent to the planet. The landing of the Viper droid was briefly witnessed by Luke Skywalker during one of his patrols, believing it to be a meteorite, although he was unable to investigate the issue further before he and his tauntaun were ambushed by a wampa and later escaped. Luke's disappearance did not go unnoticed, with General Han Solo eventually deciding to go into the snowstorm to find Skywalker when he failed to report back before the personnel were forced to close the base due to the blizzard. Skywalker managed to escape the wampa cave, also amputating one of the occupants in the process, although he was left barely alive from the encounter due to both the attack as well as from being caught in the blizzard.
Malgus, Megatron, and many of their top officers had planned a sneak attack, jumping out of hyperspace with several Nemesis and Imperial Warships at some distance from the planet and taking advantage of the fact that the meteor activity made it difficult for the Rebels to spot approaching ships. They would then initiate limited long-range orbital bombardment to destroy the base, along with any spacecraft and defenses. Major General Maximilian Veers, who somehow eventually escaped Alliance custody would then mount a sweeping ground assault to capture any survivors.
The plan would have likely allowed the Imperials to easily take the planet with few casualties. However, Admiral Ozzel made his own assault plan. He exited hyperspace close to the star system, hoping to surprise the Rebels before they could prepare their defenses. However, this backfired when the Rebels' early-warning sensors detected the fleet. The planetary shield protecting Echo Base was activated, which precluded any aerial bombardment. Veers notified Malgus, who immediately realized that Death Squadron would have to mount a full-fledged ground assault with Swatbots borrowed from Eggman and the Decepticons to take the base rather than simply destroy it from the air. An incensed Malgus Force choked Ozzel to death for his incompetence and promoted Firmus Piett, then chief fleet captain of the Star Dreadnought Executor, to Admiral.
Having assessed the situation, Malgus and Megatron ordered General Veers to land beyond the range of the energy shield and begin a surface assault aimed at knocking out the Rebels' power generator and thus bringing down the shield, while Death Squadron took up a blockade formation in an effort to prevent any fleeing Rebel starships from escaping. Veers, along with Skyward, Starscream and Shattered Glass Airachnid would command the situation on the ground while Tantor oversaw the entire engagement and issued Veers's orders from orbit via the Battlefield Holographic Control Interface.
Note: Things are heating up.