FTP로그 분석좀.. 부탁드립니다.

안녕하세요.
제가 몇일 컴퓨터를 켜놓고 자리를 비웠는데 돌아와 로그 살펴보니 이렇게 되어있네요.
Windows2000 Server 유동아이피를 사용하고 있습니다.
아이피가 바뀌는대도 어떻게 알았는지 계속 접속을 하네요.
IIS설정은 읽기/쓰기/방문기록 입니다.

----------로그 파일입니다.--------------------------
#Software: Microsoft Internet Information Services 5.0
#Version: 1.0
#Date: 2002-11-13 06:33:07
#Fields: time c-ip cs-method cs-uri-stem sc-status
06:33:07 61.223.28.179 [1]USER anonymous 331
06:33:07 61.223.28.179 [1]PASS anonymous 230
06:33:08 61.223.28.179 [1]MKD /images/2686893 550
06:33:08 61.223.28.179 [1]MKD /image/2686893 550
06:33:10 61.223.28.179 [1]MKD /ftproot/2686893 550
06:33:10 61.223.28.179 [1]MKD /mailroot/2686893 550
06:33:11 61.223.28.179 [1]MKD /wwwroot/_vti_log/2686893 550
06:33:11 61.223.28.179 [1]MKD /wwwroot/_vti_txt/2686893 550
06:33:12 61.223.28.179 [1]MKD /wwwroot/_vti_pvt/2686893 550
06:33:12 61.223.28.179 [1]MKD /wwwroot/2686893 550
06:33:13 61.223.28.179 [1]MKD /usr/incoming/2686893 550
06:33:13 61.223.28.179 [1]MKD /usr/pub/2686893 550
06:33:14 61.223.28.179 [1]MKD /usr/2686893 550
06:33:14 61.223.28.179 [1]MKD /lib/2686893 550
06:33:15 61.223.28.179 [1]MKD /cgi_bin/2686893 550
06:33:15 61.223.28.179 [1]MKD /cgi-bin/2686893 550
06:33:17 61.223.28.179 [1]MKD /bin/2686893 550
06:33:17 61.223.28.179 [1]MKD /outgoing/2686893 550
06:33:18 61.223.28.179 [1]MKD /home/2686893 550
06:33:18 61.223.28.179 [1]MKD /_private/2686893 550
06:33:19 61.223.28.179 [1]MKD /_vti_cnf/2686893 550
06:33:19 61.223.28.179 [1]MKD /_vti_log/2686893 550
06:33:20 61.223.28.179 [1]MKD /_vti_txt/2686893 550
06:33:20 61.223.28.179 [1]MKD /_vti_pvt/2686893 550
06:33:21 61.223.28.179 [1]MKD /anonymous/tmp/2686893 550
06:33:21 61.223.28.179 [1]MKD /anonymous/incoming/2686893 550
06:33:22 61.223.28.179 [1]MKD /anonymous/pub/2686893 550
06:33:22 61.223.28.179 [1]MKD /anonymous/2686893 550
06:33:23 61.223.28.179 [1]MKD /upload/incoming/2686893 550
06:33:23 61.223.28.179 [1]MKD /upload/pub/2686893 550
06:33:24 61.223.28.179 [1]MKD /2686893 257
06:33:24 61.223.28.179 [1]RMD /2686893 250