The fake account network was firing off inauthentic 'likes' and fake comments to win friends, whom it would then hit with spam.
The social media company's security team spent six months fighting what they viewed as a coordinated campaign.
"Our systems were able to identify a large portion of this illegitimate activity, and to remove a substantial number of inauthentic likes," said Shabnam Shaik, a company security manager.
Shaik added that by disrupting the campaign, Facebook expects to prevent the network of spammers from reaching its ultimate goal of sending inauthentic material to scores of people.
The fake accounts ring used accounts in a number of countries including Bangladesh, Indonesia, and Saudi Arabia.
According to Shaik, the spammers tried to mask their activities with tactics like connecting with the social network through 'proxy' servers to hide where 'likes,' posts or other communications were originating.
According to Facebook, the campaign aimed to trick people into connecting as friends, and then would later target them with spam.
The social media giant said it had scattered the operation early enough to spare users from getting spammed.
Earlier this week, Facebook said it had started weeding out fake accounts, by watching for suspicious behavior such as repetitive posts or torrents of messages.
The company described the security improvement as being part of wider efforts to rid the leading social network of misinformation, hoaxes, and fake news by verifying people's identities.
However, Facebook itself will not decide what is real and what is not, but will instead hire the Poynter Institute, a Florida journalism school, to sift through content.