An attacker can carry out an attack to disable the phone, and the phone user will not even know. At the same time mobile device will be included. The mobile device will not be able to receive incoming calls and SMS messages. On the phone screen, the connection strength indicator will show maximum value. To carry out such an attack, attackers do not contact the cellular operator. An attacker can carry out such an attack with little effort. The only thing that gives away the attack is fast discharge phone battery. The phone will drain quickly. Some phone models turn on the phone's backlight when exposed to an attack, and it does not turn off while the attack is in progress.
Such attacks create threats that could lead to disruption of important negotiations or critical situations when a work phone is needed. Sometimes such attacks are only part of big plan relative to the user.
How do attackers carry out such attacks?
The article about SMS spam describes the operating principle of SMS services. But few people know that such services can implement undocumented capabilities. Eat special type SMS messages - invisible SMS. Such SMS are not displayed on the phone screen and are not notified by the phone that it has been received. Such SMS are usually used by operators to check the existence mobile phone, but so that the user does not know about the request. Attackers can use this to carry out a DoS attack on a mobile phone.
The implementation of a DoS attack through invisible SMS is implemented because SMS messages implement a signaling layer in GSM networks. Such messages clog the signal channel. You can create generators for sending invisible messages using HTTP or SMPP protocols. The basis of invisible SMS includes simple circuit. Table 1 shows the format SMS messages. Using these parts, an SMS is generated and sent to the SMS center.
Table 1.
| Field | Size in octets | Type | Description |
|---|---|---|---|
| command_length | 4 | integer | Entire message length |
| command_id | 4 | integer | ID of the entire message |
| command_status | 4 | integer | Status |
| command_number | 4 | integer | Unique sequential number |
| service_type | 4 | string | Service type or Null |
| source_addr_ton | max 6 | integer | Sender number type |
| source_addr_npi | 1 | integer | Sender indicator |
| source_addr | 1 | string | Sender's address |
| dest_addr_ton | max 21 | integer | Recipient number type |
| dest_addr_npi | 1 | integer | Sender ID |
| dest_addr | 1 | string | Recipient's address |
| esm_class | max 21 | integer | Message Type |
| protocol_id | 1 | integer | Protocol ID |
| }
Share
 |
