[求助]请帮我看看这段记录

cove

如下<br>
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20050331 003101 127.0.0.1 POP3D (00000934) connection aborted<br>
20050331 003101 127.0.0.1 POP3D UNK: ***.com - admin<br>
20050331 003101 127.0.0.1 POP3D (00000934) logon failure for admin ***.com from 61.175.220.166<br>
20050331 003101 127.0.0.1 POP3D UNK: ***.com - admin<br>
20050331 003101 127.0.0.1 POP3D (00000660) logon failure for admin ***.com from 61.175.220.166<br>
20050331 003105 127.0.0.1 POP3D UNK: ***.com - admin<br>
20050331 003105 127.0.0.1 POP3D (00000934) logon failure for admin ***.com from 61.175.220.166<br>
20050331 003105 127.0.0.1 POP3D UNK: ***.com - admin<br>
20050331 003105 127.0.0.1 POP3D (00000660) logon failure for admin ***.com from 61.175.220.166<br>
20050331 003109 127.0.0.1 POP3D UNK: ***.com - admin<br>
20050331 003109 127.0.0.1 POP3D (00000934) logon failure for admin ***.com from 61.175.220.166<br>
20050331 003111 127.0.0.1 POP3D UNK: ***.com - admin<br>
20050331 003111 127.0.0.1 POP3D (00000660) logon failure for admin ***.com from 61.175.220.166<br>
20050331 003112 127.0.0.1 POP3D UNK: ***.com - admin<br>
20050331 003112 127.0.0.1 POP3D (00000660) logon failure for admin ***.com from 61.175.220.166<br>
20050331 003115 127.0.0.1 POP3D UNK: ***.com - admin<br>
20050331 003115 127.0.0.1 POP3D (00000934) logon failure for admin ***.com from 61.175.220.166<br>
20050331 003116 127.0.0.1 POP3D UNK: ***.com - admin<br>
20050331 003117 127.0.0.1 POP3D (00000660) logon failure for admin ***.com from 61.175.220.166<br>
20050331 003117 127.0.0.1 POP3D UNK: ***.com - admin<br>
20050331 003117 127.0.0.1 POP3D (00000660) logon failure for admin ***.com from 61.175.220.166<br>
20050331 003119 127.0.0.1 POP3D UNK: ***.com - admin<br>
20050331 003119 127.0.0.1 POP3D (00000934) logon failure for admin ***.com from 61.175.220.166<br>
20050331 003119 127.0.0.1 POP3D UNK: ***.com - admin<br>
20050331 003119 127.0.0.1 POP3D (00000660) logon failure for admin ***.com from 61.175.220.166<br>
20050331 003120 127.0.0.1 POP3D UNK: ***.com - admin<br>
20050331 003120 127.0.0.1 POP3D (00000660) logon failure for admin ***.com from 61.175.220.166<br>
20050331 003125 127.0.0.1 POP3D (00000660) logon failure for root ***.com from 61.175.220.166<br>
20050331 003125 127.0.0.1 POP3D (00000660) connection aborted<br>
20050331 003128 127.0.0.1 POP3D UNK: ***.com - backup<br>
20050331 003128 127.0.0.1 POP3D (00000660) logon failure for backup ***.com from 61.175.220.166<br>
20050331 003128 127.0.0.1 POP3D UNK: ***.com - backup<br>
......(省去百多行)<br>
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请问，这是他人在做什么才留下来的记录？通过什么方式？如果成功，会造成什么后果？怎么防范？

aaaami

应该是在尝试POP3收邮件，防范只能是设个强壮的密码，可以在服务器上可以设定尝试登陆次数等相关安全参数。