Which tunneling method uses TCP packets with the ACK bit set to carry a backdoor application?

Which tunneling method uses TCP packets with the ACK bit set to carry a backdoor application?

• A. ACK tunneling
• B. AckCmd
• C. HTTP Tunneling
• D. ICMP tunneling

Answer: (A)

ACK tunneling relies on using TCP packets that have the ACK flag set to transmit a backdoor payload. In this approach, commands or data are carried within legitimate-looking TCP ACK traffic, so the backdoor can communicate over a normal TCP session without triggering obvious alarms. The ACK bit acts as a signaling mechanism within the TCP flow, making the channel difficult to distinguish from ordinary traffic because it doesn’t rely on a separate protocol like HTTP or ICMP. This stealthy use of TCP ACK packets for covert data exchange is what defines this tunneling method.

ACK tunneling relies on using TCP packets that have the ACK flag set to transmit a backdoor payload. In this approach, commands or data are carried within legitimate-looking TCP ACK traffic, so the backdoor can communicate over a normal TCP session without triggering obvious alarms. The ACK bit acts as a signaling mechanism within the TCP flow, making the channel difficult to distinguish from ordinary traffic because it doesn’t rely on a separate protocol like HTTP or ICMP. This stealthy use of TCP ACK packets for covert data exchange is what defines this tunneling method.