It indicates a possible exploit of a denial of service vulnerability in various modems.
An attacker can send an AT command to a remote computer that responds to commands, such as ctcp, ping, and icmp, to cause the modem on the responding computer to execute the received commands. This attack can be performed on any computer with a Global Village modem.
Any application Any version
Denial of service
Disable the escape "+++" by setting the S2 register to a value of:
127 for 7-bit modems
256 for 8-bit modems