What exactly was in Pandora's Box?
Theoi suggests that the overall name for the evil spirits might be Keres:
The Keres may have been the evil spirits released from Pandora's jar to plague mankind. Hesiod mentions them indirectly in his account of the episode. He describes these spirits as kakoi (evils), nosoi (sicknesses and plagues) and lugra (banes).
They are mentioned both above and within the passage Yannis cites:
"For ere this [the opening of Pandora's jar] the tribes of men lived on earth remote and free from ills (kakoi) and hard toil (ponoi) and heavy sickness (nosoi) which bring the Keres (Fates) upon men; for in misery men grow old quickly. But the woman took off the great lid of the jar (pithos) with her hands and scattered all these and her thought caused sorrow and mischief to men. Only Elpis (Hope) remained there in an unbreakable home within under the rim of the great jar, and did not fly out at the door; for ere that, the lid of the jar stopped her, by the will of Aigis-holding Zeus who gathers the clouds. But the rest, countless plagues (lugra), wander amongst men; for earth is full of evils and the sea is full. Of themselves diseases (nosoi) come upon men continually by day and by night, bringing mischief to mortals silently; for wise Zeus took away speech from them. So is there no way to escape the will of Zeus."
Note that this is a fair degree of leeway in translating kakoi, nosoi, ponoi and lugra, thus no single translation is definitive.