Have you received an unusual amount of strange phone calls on a mobile or land line recently? If so, you should be aware of a scam that uses automated phone calls to gain access to users’ accounts, leaving its victims with drained bank accounts. It’s a rare example of Telephony Denial of Service (TDOS) attacks being used directly against consumers.

The FBI website describes the phony phone call scheme:

During these TDOS attacks, online trading and other money management accounts are being accessed by the perpetrators who are transferring funds out of those accounts. The perpetrators will obtain account information of their victims in some way and then contact the financial institutions to change their victims’ profile information such as email addresses, telephone numbers and bank account numbers. The purpose of the malicious phone calls is to occupy the victim phone numbers on record with the financial institutions managing the accounts so that when the institutions contact the victim to verify the changes and transactions, the institution is unable to reach the victim. Consequently, the victim has no idea what has really transpired until it’s too late.

The calls, typically made in such a volume as to overwhelm the targeted line, can be identified as dead air (silence on the other end), an ‘innocuous recorded message’, advertisement or even a phony telephone sex menu. The FBI recommends anyone who suspects they may be the target of such an attack should contact their telephone service provider in addition to alerting their financial institutions.