A sharp rise in spam flowing to users of Google’s Gmail service took place last month when hackers broke through a security tool used to prevent the junk mail, according to MessageLabs research reported by ZDNet Australia.
Apparently hackers have figured out a way to break common security software called “captcha” that asks the user to decipher and enter a series of letters and numbers displayed in a distorted way on the screen before they can sign up for an email account.
Last month it was Gmail’s turn, after Yahoo Mail and Hotmail were breached last year, lifting the proportion of spam to authorised email in Gmail accounts from 1.3% in January to 2.6% in February.
A Google representative said she could not confirm or deny that the captcha method used in Gmail had been broken, but did confirm that there had been an increase in spam recently.