Twitter members are warned to be on their guard against an evolving attack which threatens to steal personal information from them.
According to Sophos, thousands of Twitter users are reporting having received direct messages from friends inviting them to visit a website. Sometimes the lure claims that they could win an Apple iPhone, and on other occasions the messages have pretended to point to funny pictures or blog articles about the recipients.
The original messages over the weekend pretended to point to funny pictures or blog articles about the recipients, with subject lines "Hey, i found a website with your pic on it… LOL check it out here" or "hey! check out this funny blog about you…".
However, clicking on the links would take users to a bogus Twitter page which would steal users' login name and passwords.
Writer, TV star and Twitter celebrity Stephen Fry was among the people who unwittingly clicked on the link without realising that he was being taken to a potentially dangerous website although it is not believed that his account has been compromised.
Sophos experts note that having hacked into Twitter accounts with information gleaned from the widespread phishing attack, cybercriminals are then using the compromised Twitter identities to pass on spam messages to even more Twitter users.
These new messages are claiming that recipients could win an Apple iPhone if they visit a web link.
"It would be bad enough to hand your Twitter username and password over to a criminal, as they could pose as you online and spread malware and spam to your friends and followers. However, as an alarming 41% of internet users foolishly use the same username and password for every website they access, the potential for abuse is even greater," says Brett Myroff, CEO of regional Sophos distributor, Sophos South Africa.
"Twitter users who may have lost control of their accounts need to change their passwords as a matter of priority before more harm is done. Compromised social networking accounts are valuable for hackers as they can use them for a springboard for spam campaigns, identity theft attacks and other online crime."