๋‚˜๋Š” ๋‚ด ๊ตํ†ต ์ƒํ™ฉ์„ ์‚ดํŽด๋ณด์•˜์Šต๋‹ˆ๋‹ค. ๊ทธ๋Š” ๋‚˜์— ๋Œ€ํ•ด ๋ชจ๋“  ๊ฒƒ์„ ์•Œ๊ณ  ์žˆ์—ˆ์Šต๋‹ˆ๋‹ค(Mac OS Catalina).

๋‚˜๋Š” ๋‚ด ๊ตํ†ต ์ƒํ™ฉ์„ ์‚ดํŽด๋ณด์•˜์Šต๋‹ˆ๋‹ค. ๊ทธ๋Š” ๋‚˜์— ๋Œ€ํ•ด ๋ชจ๋“  ๊ฒƒ์„ ์•Œ๊ณ  ์žˆ์—ˆ์Šต๋‹ˆ๋‹ค(Mac OS Catalina).๋จธ๋ฆฌ์— ์ข…์ด๋ด‰ํˆฌ๋ฅผ ์ด๊ณ  ์žˆ๋Š” ๋‚จ์ž

์˜ค๋Š˜ Catalina๋ฅผ 15.6์—์„œ 15.7๋กœ ์—…๋ฐ์ดํŠธํ•œ ํ›„ ์ธํ„ฐ๋„ท ์†๋„๊ฐ€ ๋–จ์–ด์ง€๊ณ  ๋ญ”๊ฐ€ ๋„คํŠธ์›Œํฌ์— ๊ณผ๋ถ€ํ•˜๊ฐ€ ๊ฑธ๋ ค์„œ ๋„คํŠธ์›Œํฌ ํ™œ๋™์„ ์‚ดํŽด๋ณด๊ธฐ๋กœ ๊ฒฐ์ •ํ–ˆ์Šต๋‹ˆ๋‹ค.

๋‚˜๋Š” ๋ช‡ ์‹œ๊ฐ„ ๋™์•ˆ tcpdump๋ฅผ ์‹คํ–‰ํ–ˆ์Šต๋‹ˆ๋‹ค.

sudo tcpdump -k NP > ~/log 

๊ทธ๋ฆฌ๊ณ  ๊ฐ€์žฅ ๋จผ์ € ๋‚ด ๋ˆˆ๊ธธ์„ ์‚ฌ๋กœ์žก์€ ๊ฒƒ์€:

16:43:42.919443 () ARP, Request who-has 192.168.1.51 tell 192.168.1.1, length 28
16:43:42.927716 () ARP, Request who-has 192.168.1.52 tell 192.168.1.1, length 28
16:43:42.934112 () ARP, Request who-has 192.168.1.53 tell 192.168.1.1, length 28
16:43:42.942328 () ARP, Request who-has 192.168.1.54 tell 192.168.1.1, length 28
16:43:43.021971 () ARP, Request who-has 192.168.1.55 tell 192.168.1.1, length 28

์™œ ๋‚ด ์ „์ฒด ๋กœ์ปฌ ๋„คํŠธ์›Œํฌ๊ฐ€ ํ•„์š”ํ•œ๊ฐ€์š”? 192.168.1./255 XNUMX๋ถ„๋งˆ๋‹ค ๋์—†์ด ์Šค์บ”ํ•ฉ๋‹ˆ๋‹ค. ์ข‹์Šต๋‹ˆ๋‹ค. ์ด๊ฒƒ์ด ๋„คํŠธ์›Œํฌ ๋ธŒ๋ผ์šฐ์ € ์„œ๋น„์Šค๋ผ๊ณ  ๊ฐ€์ •ํ•ด ๋ณด๊ฒ ์Šต๋‹ˆ๋‹ค.

(shadowserver.org) โ€” ๋น„์˜๋ฆฌ ๋ณด์•ˆ ๋‹จ์ฒด

16:43:33.518282 () IP scan-05l.shadowserver.org.33567 > 192.168.1.150.rsync: Flags [S], seq 1527048226, win 65535, options [mss 536], length 0

๋˜ ๋‹ค๋ฅธ ๋ฌธ๊ณ ๋ฆฌ(scanner-12.ch1.censys-scanner.com -> censys.io):

16:44:16.254073 () IP scanner-12.ch1.censys-scanner.com.62651 > 192.168.1.150.8843: Flags [S], seq 1454862354, win 1024, options [mss 1460], length 0

์ข‹์•„์š”, ์ข‹์•„์š”, ํŠน๋ณ„ํ•œ ๊ฒƒ์€ ์•„๋‹Œ ๊ฒƒ ๊ฐ™์Šต๋‹ˆ๋‹ค. ๋ถ„์„, ๋กœ์ปฌ ๋„คํŠธ์›Œํฌ ๊ฒ€์ƒ‰ ๋“ฑ์€ ์ผ๋ฐ˜์ ์ธ ์ผ์ด์ง€๋งŒ ๋‹ค์Œ์€ ์–ด๋–ป์Šต๋‹ˆ๊นŒ?

16:15:56.603292 () IP 45.129.33.152.51777 > 192.168.1.150.jpegmpeg: Flags [S], seq 2349838714, win 1024, options [mss 536], length 0

์ด IP ์ฃผ์†Œ๋กœ ์ด๋™ํ•˜๋ฉด http://45.129.33.152, ๋‹ค์Œ์„ ๋ณผ ์ˆ˜ ์žˆ์Šต๋‹ˆ๋‹ค.

๋‚˜๋Š” ๋‚ด ๊ตํ†ต ์ƒํ™ฉ์„ ์‚ดํŽด๋ณด์•˜์Šต๋‹ˆ๋‹ค. ๊ทธ๋Š” ๋‚˜์— ๋Œ€ํ•ด ๋ชจ๋“  ๊ฒƒ์„ ์•Œ๊ณ  ์žˆ์—ˆ์Šต๋‹ˆ๋‹ค(Mac OS Catalina).ํ…์ŠคํŠธ ํŒŒ์ผ์—๋Š” ํฌํŠธ๊ฐ€ ์žˆ๋Š” ์ˆ˜๋ฐฑ๋งŒ ๊ฐœ์˜ IP ์ฃผ์†Œ๊ฐ€ ํฌํ•จ๋˜์–ด ์žˆ์Šต๋‹ˆ๋‹ค.

์ž„์‹œ ํŒŒ์ผ์˜ ๋‚ด์šฉ:

[?1h=[?25l[H[J[mtop - 21:17:26 up 31 days,  6:44,  1 use[m[39;49m[m[39;49m[K
Tasks:[m[39;49m[1m 144 [m[39;49mtotal,[m[39;49m[1m   1 [m[39;49mrunning,[m[39;49m[1m 143 [m[39;49msleep[m[39;49m[m[39;49m[K
%Cpu(s):[m[39;49m[1m  0.8 [m[39;49mus,[m[39;49m[1m  0.0 [m[39;49msy,[m[39;49m[1m  0.0 [m[39;49mni,[m[39;49m[1m 92.0[m[39;49m[m[39;49m[K
KiB Mem :[m[39;49m[1m 32681700 [m[39;49mtotal,[m[39;49m[1m 18410244 [m[39;49mfree,[m[39;49m[m[39;49m[K
KiB Swap:[m[39;49m[1m 16449532 [m[39;49mtotal,[m[39;49m[1m 16449288 [m[39;49mfree,[m[39;49m[m[39;49m[K
[K
[7m  PID USER      PR  NI    VIRT    RES [m[39;49m[K
[m    1 root      20   0  191072   3924 [m[39;49m[K
[m    2 root      20   0       0      0 [m[39;49m[K
[m    3 root      20   0       0      0 [m[39;49m[K
[m    5 root       0 -20       0      0 [m[39;49m[K
[m    7 root      rt   0       0      0 [m[39;49m[K
[m    8 root      20   0       0      0 [m[39;49m[K
[m    9 root      20   0       0      0 [m[39;49m[K
[m   10 root      rt   0       0      0 [m[39;49m[K
[m   11 root      rt   0       0      0 [m[39;49m[K
[m   12 root      rt   0       0      0 [m[39;49m[K
[m   13 root      20   0       0      0 [m[39;49m[K
[m   15 root       0 -20       0      0 [m[39;49m[K
[m   16 root      rt   0       0      0 [m[39;49m[K[H[mtop - 21:17:29 up 31 days,  6:44,  1 use[m[39;49m[m[39;49m[K

%Cpu(s):[m[39;49m[1m  0.0 [m[39;49mus,[m[39;49m[1m  0.0 [m[39;49msy,[m[39;49m[1m  0.0 [m[39;49mni,[m[39;49m[1m100.0[m[39;49m[m[39;49m[K
KiB Mem :[m[39;49m[1m 32681700 [m[39;49mtotal,[m[39;49m[1m 18409876 [m[39;49mfree,[m[39;49m[m[39;49m[K

[K

๊ทธ๋ฆฌ๊ณ  ๋งˆ์ง€๋ง‰์œผ๋กœ, ์•Œ๋ ค์ง€์ง€ ์•Š์€ ์—ฌ๋Ÿฌ ์ฟผ๋ฆฌ๊ฐ€ ์žˆ์Šต๋‹ˆ๋‹ค.

16:16:07.022910 () IP 059148253194.ctinets.com.58703 > 192.168.1.150.4244: Flags [S], seq 2829545743, win 1024, options [mss 536], length 0
16:15:57.133836 () IP 45.129.33.2.55914 > 192.168.1.150.39686: Flags [S], seq 700814637, win 1024, options [mss 536], length 0
16:15:56.603292 () IP 45.129.33.152.51777 > 192.168.1.150.jpegmpeg: Flags [S], seq 2349838714, win 1024, options [mss 536], length 0
16:16:15.083755 () IP 45.129.33.154.55846 > 192.168.1.150.7063: Flags [S], seq 4079154719, win 1024, options [mss 536], length 0
16:15:43.251305 () IP 192.168.1.150.60314 > one.one.one.one.domain: 3798+ PTR? 237.171.154.149.in-addr.arpa. (46)
16:16:24.386628 () IP 45.141.84.30.50763 > 192.168.1.150.12158: Flags [S], seq 572523718, win 1024, options [mss 536], length 0
16:16:44.817035 () IP 92.63.197.66.58219 > 192.168.1.150.15077: Flags [S], seq 4012437618, win 1024, options [mss 536], length 0
16:15:43.172042 () IP 45.129.33.46.51641 > 192.168.1.150.bnetgame: Flags [S], seq 362771723, win 1024, options [mss 536], length 0
16:17:02.120063 () IP 45.129.33.23.42275 > 192.168.1.150.11556: Flags [S], seq 3354007029, win 1024, options [mss 536], length 0
16:16:00.589816 () IP 45.129.33.3.56005 > 192.168.1.150.40688: Flags [S], seq 2710391040, win 1024, options [mss 536], length 0

ํ˜ธ์ŠคํŠธ ํŒŒ์ผ์—์„œ ์ด๋Ÿฌํ•œ ๋„๋ฉ”์ธ๊ณผ IP ์ฃผ์†Œ๋ฅผ ์ฐจ๋‹จํ•˜๋ฉด ๋‹ค์Œ ๋คํ”„์—๋Š” ๋™์ผํ•œ IP ์„œ๋ธŒ๋„ท์ด ์žˆ์ง€๋งŒ ์ตœ์ข… ์ฃผ์†Œ๋Š” ๋‹ค๋ฅด๋ฉฐ ๋„๋ฉ”์ธ์˜ ํ•˜์œ„ ๋„๋ฉ”์ธ์ด ๋ณ€๊ฒฝ๋ฉ๋‹ˆ๋‹ค.

Mac์ด ํ˜ธ์ŠคํŠธ ํŒŒ์ผ *.example.com์˜ ๋งˆ์Šคํฌ๋ฅผ ์ธ์‹ํ•˜์ง€ ๋ชปํ•ฉ๋‹ˆ๋‹ค.

์ „์†ก๋˜๋Š” ํŒจํ‚ท์„ ์–ด๋–ป๊ฒŒ ๋ณด๋Š”์ง€, ์–ด๋–ค ํ”„๋กœ์„ธ์Šค๋‚˜ ๋ฐ๋ชฌ์ด ์ด๋Ÿฌํ•œ ์—ฐ๊ฒฐ์„ ์œ ๋ฐœํ•˜๋Š”์ง€ ํŒŒ์•…ํ•˜์ง€ ๋ชปํ–ˆ์ง€๋งŒ(์ €๋Š” ๋ฉฐ์น  ๋™์•ˆ Mac์„ ์‚ฌ์šฉํ–ˆ์Šต๋‹ˆ๋‹ค) ๋ฒŒ์จ ์žฌ๋ฏธ์žˆ์Šต๋‹ˆ๋‹ค!

์ถœ์ฒ˜ : habr.com