The social sharing app Buffer had been compromised which sent out spam weight-loss tweets and posts on user's Twitter and Facebook pages.
The app users, however, were then advised to change their Facebook passwords or cancel the application's social sharing permissions, and erase the spam posts from their Facebook timelines.
The firm Tweeted: "Hi all. So sorry, it looks like we've been compromised."
"Temporarily pausing all posts as we investigate. We'll update ASAP," the tweet said.
Following attacks, the company has claimed that it has improved its security to avoid such attacks in future.
Any user posts scheduled during the outage would be listed as 'failed,' and users have to log in and link their Twitter accounts again, while Facebook accounts must still have to be linked as they were before the latest attack.
Facebook reported that around 30,000 Buffer users had been hit with the attack, while the service has been reportedly resumed with enhanced security following the incidents.
Buffer's CEO Joel Gascoigne said that no billing or payment information was affected or exposed to the hackers during the attack.
"We're working with several security experts on tracking down exactly how it was possible for the spammers to get into our system," Gascoigne said.
"We're making good progress on this, this morning."