Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/bcad7aa6cb6cb9d94377cd88acbca1c9.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln

Threat: Worm.Win32.Busan.k
Vulnerability: Insecure Communication Protocol
Description: Busan.k launches a windows cmd console on the infected host so that it can send and receive messages back and forth over TCP port 2121. The worm uses unencrypted plaintext socket communication allowing anyone who can sniff network traffic to read any communications sent or retrieved. This can disclose sensitive information to third-party well positioned attackers.
Type: PE32
MD5: bcad7aa6cb6cb9d94377cd88acbca1c9
Vuln ID: MVID-2021-0185
Dropped files: 
Disclosure: 04/23/2021


Exploit/PoC:
E.g. Wireshark to sniff communications.

18  24.610339  192.168.88.130  192.168.88.128  TCP  68  56103 → 2121 [PSH, ACK] Seq=1 Ack=1 Win=8212 Len=14
0000   00 XX XX XX XX XX 00 XX XX XX XX XX 08 00 45 00  ..).....)R....E.
0010   00 36 cc 00 40 00 80 06 00 00 c0 a8 58 82 c0 a8  .6..@.......X...
0020   58 80 db 27 08 49 3c 1a 3c 74 fc c1 08 dd 50 18  X..'.I<.<t....P.
0030   20 14 32 7c 00 00 70 61 73 73 77 64 20 61 62 63   .2|..passwd abc
0040   31 32 33 0a                                      123.

0000   00 XX XX XX XX XX 00 XX XX XX XX XX 08 00 45 00  ..)R....).....E.
0010   00 34 1e c4 40 00 80 06 a9 ac c0 a8 58 80 c0 a8  .4..@.......X...
0020   58 82 08 49 db 27 fc c1 08 dd 3c 1a 3c 82 50 18  X..I.'....<.<.P.
0030   08 05 50 dc 00 00 49 20 68 61 74 65 20 79 6f 75  ..P...I hate you
0040   0d 0a                                            ..

0000   00 XX XX XX XX XX 00 XX XX XX XX XX 08 00 45 00  ..).....)R....E.
0010   00 38 cc 02 40 00 80 06 00 00 c0 a8 58 82 c0 a8  .8..@.......X...
0020   58 80 db 27 08 49 3c 1a 3c 82 fc c1 08 e9 50 18  X..'.I<.<.....P.
0030   20 14 32 7e 00 00 49 20 68 61 74 65 20 79 6f 75   .2~..I hate you
0040   20 74 6f 6f 21 0a                                 too!.


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