Berlin The fraudulent phone numbers can be recognized by a sequence of digits, which are indicated with an asterisk, warns the trade magazine. For Germany, the combination is **21*, in previous cases – especially in India – goods were preceded by the phone number **67* or *405*. Attention: Fraud by control commands However, the characters that initially appear harmless are a so-called GSM code that serves as a control command for smartphones. This allows fraudsters to set up call redirects and call blocks – and ultimately redirect all calls to the fraudsters’ devices. What happens after a call to this number? According to Computer Bild, criminals take over the Whatsapp accounts of their victims and deposit their own smartphone as a new device. Since a new device on Whatsapp can usually be confirmed by a control call, verification by means of call forwarding is no problem. The trade magazine warns that fraudsters can legitimize themselves as users of the account and possibly also change the phone numbers and thus gain full control over the account. After fraud, the account is gone for the first time, which means: it will be difficult to get your own account back, since fraudsters can now log in. The trade magazine warns that fraudsters use the circumstance and send messages to their own contacts on behalf of the victims or spread the manipulated phone number further in order to take over other accounts.