Term for "people paid to post bad reviews of a product"
The term you are looking for is:
Sock-puppeteer:
(They operate with their Sockpuppet identity)
Sock puppet marketing is one example of astroturfing.
A 'sockpuppet' (one word) is a false identity, a made up person which is manipulated to appear as if they have done specific things or have a particular opinion about something.
Sock puppet marketing is one example of astroturfing, the practice of artificially stimulating online conversation and positive reviews about a product, brand or service. Because sock puppets can be created quickly and do not need to be maintained, they are often used on social media sites to grow public interest or conversely, denigrate a competitor’s product, brand or service.
Further reading,
- Sockpuppeting
- Sock puppet marketing
Usage in NEW YORK TIMES: "Ethel Stein, a weaver who created countless intricate textile artworks and one particularly influential sock-puppet, died on Friday in Cortlandt, N.Y."
Your Example: "My company hired sockpuppeteer to smear its competition in on-line reviews, but we had to apologize after being found out."
On the other hand,
Cyber-Shill
Cyber shill's main job is to promote employers product or service online. It, does not necessarily mean that they are hired to actively denigrate a competitor’s product, brand or service.
An Internet shill is someone who promotes something or someone online for pay without divulging that they are associated with the entity they shill for.
Example,
1) huffingtonpost.com,
A group of researchers at UCSB studied the growing practice of hiring cyber shills who are paid to manually inflate positive reviews and ratings. Such companies have existed for some time in the United States. including ShortTask.com, Microworkers.com, and MyEasyTask.com. Because of labor costs, however, most are focused on improving search engine optimization using software programs and processes.
Shill: An accomplice of a hawker, gambler, or swindler who acts as an enthusiastic customer to entice or encourage others.
Oxford dictionary gives a particular definition on the word SHILL, which explicitly highlights on the aspect of promotion. Shills are not actively working to denigrate your competitor's product/brand/services/etc.
An accomplice of a confidence trickster or swindler who poses as a genuine customer to entice or encourage others.