The aliens (let's just call them the Zorks) send out a gift to humanity: UNLIMITED GOLD!
However, they botch the aerobraking and lithobreaking procedures by an astronomical unit. Whatever ship full of butter they sent just made an Earth-kabob, punching out the core, stopping the natural spin (thereby dooming everyone on the top to death by friction,) and then moving Earth from its orbit. Death rate: 84.2745%. A bunch of Germans, Russians, and some Nigerians remain.
However, they also sent a large space station complex with it as well. Whatever's left of the Earth goes and takes the spaceships included with the main craft and moves to the space station. However, they discover that they can't get very much of the gold to the station, and furthermore - the station's life support runs on gold. Oops.
However, they find a warp pad on the station. It's labeled in feet, but nobody bothers to check the math on the instruction manual: whatever language the aliens have, their word for feet is more like a millimeter. The humans accidentally end up gapping their new home in half. Death rate: 98.348572%. Only a few Germans and a Russian remain. The Russian has the wise idea to get to the shuttles, which have infinite life support. He punches the warp drive, but finds him stranded on Mars due to really slow acceleration. He is killed in the resulting planetary collapse.
Humanity dies from a humiliation conga. If only the aliens hadn't tried to embed the ship in the planet...
Alternatively, let's say the Zorks are like the <PERSON> from Farscape: they're highly allergic to heat. The <PERSON> are of the misconception that every form of life is allergic to life, and so they develop planetary heat shields.
They send these out in random directions, just hoping they hit a planet: any planet. 99
As luck would have it, one hits Earth. Thankfully, they did write SOLAR RADIATION CANCELLATION DEVICE on it, but Israel is dead tired of being in the sweltering sun all day. They pull the lever (against orders from Ukraine, China, Austria, Argentina and Burma) and get themselves nuked for it. Not only does the solar heat suddenly vanish, solar panels (which have become the only source of power, because ten years prior the world had just expended their last drop of oil and their last puff of natural gas) stop providing power, the world just wound up in nuclear warfare. Meanwhile, the Zorks are laughing their butts off, thinking to themselves "they were actually going to go to war over solar radiation? Those guys must be insane!"
But in another universe, the <PERSON> actually receive something from Earth: the Voyager 1 space probe. Seeing as how the people of Earth like music, they send lots of musical robots to Earth, hoping that they can help improve economic conditions by making all of the Earth fertile. Soon, every one of the robots is activated by humanity, enjoyed by humanity... and is busy paving the Earth with soil. The only water on Earth is accidentally buried under tonnes of dirty-looking dirt. They then do the same process to the Moon, except they make it water: an irrigation system. Humanity is accidentally plowed and watered. The guys on the ISS move to the Moon, building a small society. The confused Zorks watch in horror as humanity seemingly vanishes from Earth: they love to eat, and were going to send new ovens and grills to Earth once they got started. But alas, the Zorks are now drowning in cooking appliances that went unused. They issue Order 66, which is for the robots to blare "HEY COME FARM!" really loud. The people on the Moon last ten years before the last one dies of ear collapse. 99