이런 해킹기법이 무엇인지요??

다음과 같이 특정 포트로 수십개정도 접속이 이루어집니다.

이때 나타나는 현상이  CPU 및 MEMORY 사용률이 높아짐니다..공격자 IP를 막는 방법으로 조치를 취하고 있지만...도대체 이런 해킹 기법이 무엇인지 궁금합니다.

2603는 저희가 사용하는 포트입니다.

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tcp4       0   1024  192.168.0.10.2603     124.0.24.188.46356     ESTABLISHED
tcp   -1057776904 120517008  0:0:72e:f088::.1838    0:0:72e:f070::.1838    CLOSED
tcp4       0   1024  192.168.0.10.2603     124.0.24.188.46356     ESTABLISHED
tcp   -1057776904 120517008  0:0:72e:f088::.1838    0:0:72e:f070::.1838    CLOSED
tcp4       0   1024  192.168.0.10.2603     124.0.24.188.46356     ESTABLISHED
tcp   -1057776904 120517008  0:0:72e:f088::.1838    0:0:72e:f070::.1838    CLOSED
tcp4       0   1024  192.168.0.10.2603     124.0.24.188.46356     ESTABLISHED
tcp   -1057776904 120517008  0:0:72e:f088::.1838    0:0:72e:f070::.1838    CLOSED
tcp4       0   1024  192.168.0.10.2603     124.0.24.188.46356     ESTABLISHED
tcp   -1057776904 120517008  0:0:72e:f088::.1838    0:0:72e:f070::.1838    CLOSED
tcp4       0   1024  192.168.0.10.2603     124.0.24.188.46356     ESTABLISHED
tcp   -1057776904 120517008  0:0:72e:f088::.1838    0:0:72e:f070::.1838    CLOSED
tcp4       0   1024  192.168.0.10.2603     124.0.24.188.46356     ESTABLISHED
tcp   -1057776904 120517008  0:0:72e:f088::.1838    0:0:72e:f070::.1838    CLOSED
tcp4       0   1024  192.168.0.10.2603     124.0.24.188.46356     ESTABLISHED
tcp   -1057776904 120517008  0:0:72e:f088::.1838    0:0:72e:f070::.1838    CLOSED
tcp4       0   1024  192.168.0.10.2603     124.0.24.188.46356     ESTABLISHED
tcp   -1057776904 120517008  0:0:72e:f088::.1838    0:0:72e:f070::.1838    CLOSED
tcp4       0   1024  192.168.0.10.2603     124.0.24.188.46356     ESTABLISHED