The Pandora myth is thought to have originally appeared in lines 560-612 of Hesiod's (ca. 8th-7th centuries BC) epic poem, the Theogony, although the woman in this piece is unnamed. The following is a summary of the Theogeny.
After bestowing the gift of fire from Prometheus, an angry Zeus decides to bestow a punishment on mankind to compensate for the boon they have been given. He commands Hephaestus to mould from earth the first woman, a "beautiful evil" whose descendants would torment the race of men. Athena dresses the woman in a silvery gown, an embroidered veil, garlands, and an ornate crown of gold.
When the woman first appears before gods and mortals, "wonder seized them" as they looked upon her. But she was "sheer guile, not to be withstood by men."
Hesiod elaborates (590-93):
From her is the race of women and female kind:
of her is the deadly race and tribe of women who
live amongst mortal men to their great trouble,
no helpmeets in hateful poverty, but only in wealth.
Hesiod goes on to lament that men who try to avoid the evil of women by avoiding marriage will fare no better (604-7):
He reaches deadly old age without anyone to tend his years,
and though he at least has no lack of livelihood while he lives,
yet, when he is dead, his kinsfolk divide his possessions amongst them.
Hesiod concedes that occasionally a man finds a good wife, but still (609) "evil contends with good."
Hesiod revisists the Pandora myth Hesiod in his Works and Days.
Here is the Wikipedia entry for Pandora: