This scam has appeared on Twitter recently. There are a few minor variations but they all seem to work the same. It starts with a Twitter message saying,
I will follow back if you follow me
There’s a link at the end of the message that goes to a web page. On this page are two signup options, one free and a paid one called VIP.
The free one asks for your Twitter username and password. It then asks prompts Twitter to grant you access to your account. You should not enter these details into any untrusted service.
Once they have your account password they send spam using your Twitter account, sending them to this same web site.
The VIP service is just as bad. It asks for your credit card details and Twitter account details, promising hundreds of Twitter followers. People who fall for this also end up sending spam from their own account, with the added risk of losing money.
Please help stop this scam by letting people know about it.