DotNet First Side: Apr 16, 2020

Thursday, April 16, 2020

Linux Stack Protection By Default

Modern gcc compiler (v9.2.0) protects the stack by default and you will notice it because instead of SIGSEGV on stack overflow you will get a SIGABRT, but it also generates coredumps.

In this case the compiler adds the variable local_10. This variable helds a canary value that is checked at the end of the function.
The memset overflows the four bytes stack variable and modifies the canary value.

The 64bits canary 0x5429851ebaf95800 can't be predicted, but in specific situations is not re-generated and can be bruteforced or in other situations can be leaked from memory for example using a format string vulnerability or an arbitrary read wihout overflowing the stack.

If the canary doesn't match, the libc function __stack_chck_fail is called and terminates the prorgam with a SIGABORT which generates a coredump, in the case of archlinux managed by systemd and are stored on "/var/lib/systemd/coredump/"

❯❯❯ ./test
*** stack smashing detected ***: terminated
fish: './test' terminated by signal SIGABRT (Abort)

❯❯❯ sudo lz4 -d core.test.1000.c611b7caa58a4fa3bcf403e6eac95bb0.1121.1574354610000000.lz4
[sudo] password for xxxx:
Decoding file core.test.1000.c611b7caa58a4fa3bcf403e6eac95bb0.1121.1574354610000000
core.test.1000.c611b : decoded 249856 bytes

❯❯❯ sudo gdb /home/xxxx/test core.test.1000.c611b7caa58a4fa3bcf403e6eac95bb0.1121.1574354610000000 -q

We specify the binary and the core file as a gdb parameters. We can see only one LWP (light weight process) or linux thread, so in this case is quicker to check. First of all lets see the back trace, because in this case the execution don't terminate in the segfaulted return.

We can see on frame 5 the address were it would had returned to main if it wouldn't aborted.

Happy Idea: we can use this stack canary aborts to detect stack overflows. In Debian with prevous versions it will be exploitable depending on the compilation flags used.
And note that the canary is located as the last variable in the stack so the previous variables can be overwritten without problems.

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CLOUDKiLL3R - Bypasses Cloudflare Protection Service Via TOR Browser

CLOUDKiLL3R bypasses Cloudflare protection service via TOR Browser !

CLOUDKiLL3R Requirements :

TOR Browser to scan as many sites as you want :)
Python Compiler

CLOUDKiLL3R Installation ?
Make sure that TOR Browser is up and running while working with CLOUDKiLL3R .
Make sure that the IP AND PORT are the same in TOR Browser preferences > advanced > Networks
Include the files below in one folder :

FILTER.txt
CK.pl

Make Sure The Modules Below Are Installed If NOT > use this command to install one : pip install [module name]

argparse
socks
socket
requests
sys

Contact :
Twitter.com/moh_security

Download CLOUDKiLL3R

Read more

Linux.Agent Malware Sample - Data Stealer

Research: SentinelOne, Tim Strazzere Hiding in plain sight?
Sample credit: Tim Strazzere

List of files

9f7ead4a7e9412225be540c30e04bf98dbd69f62b8910877f0f33057ca153b65 malware
d507119f6684c2d978129542f632346774fa2e96cf76fa77f377d130463e9c2c malware
fddb36800fbd0a9c9bfffb22ce7eacbccecd1c26b0d3fb3560da5e9ed97ec14c script.decompiled-pretty
ec5d4f90c91273b3794814be6b6257523d5300c28a492093e4fa1743291858dc script.decompiled-raw
4d46893167464852455fce9829d4f9fcf3cce171c6f1a9c70ee133f225444d37 script.dumped

malware_a3dad000efa7d14c236c8018ad110144
malware fcbfb234b912c84e052a4a393c516c78
script.decompiled-pretty aab8ea012eafddabcdeee115ecc0e9b5
script.decompiled-raw ae0ea319de60dae6d3e0e58265e0cfcc
script.dumped b30df2e63bd4f35a32f9ea9b23a6f9e7

Download

Download. Email me if you need the password

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How To Start PHP And MYSQL | The Best Server For PHP And MYSQL | Tutorial 1

Many of people want to start PHP programming embedded with MYSQL databases concepts. So i thought that I should start a series about PHP and MYSQL. So in this series of video tutorials you exactly got the content about PHP and MYSQL.

As PHP is server side scripting language. So it requires a server to get execute over the web browser. First of all you have to download and install a server that may be XAMPP, WAMPP or LAMPP. I'm using XAMPP server in the tutorials. So if you wanna follow me then download a XAMPP server. I'm using this because it has a good interface to work and it's really simple. XAMPP is compatible with windows, MAC and Linux operating as well. WAMPP is only for windows and LAMPP is used for MAC and Linux operating system. So i prefer XAMPP for this series.

How to create Database

Step 1:

Open Your XAMPP control panel and start Apache and Mysql services.

Step 2:

Go to your Web browser and type "localhost/phpmyadmin". It will open your databases area. If you have an error then your services are not in running state. If you have any error then comment below.

Step 3:

Click over the "new" to create a new database.

Step 4:

Write Database_Name and click over the Create button. For example Facebook, Students etc.

Step 5:

Write Table_Name like admin, users etc. your can increase and decrease the size of rows. Click over Save/Create button.

Step 6:

Write your Attribute_Names in first column like Username, Email, Passwords etc. In the next data type column you have to select the data type whether it is integer or string type etc. In the next column you have to set the length of string/words.

Step 7:

If you wanna go through with a Primary_Key. Then just you have to checked the Auto_Increment box as you will shown in the video. For further watch the video for better understanding.