مت کرو بحث ہار جاؤ گی- حسن اتنی بڑی دلیل نہیں- "جون ایلیا"



آج بھی تشنگی کی قسمت میں
سمِ قاتل ہے سلسبیل نہیں

سب خدا کے وکیل ہیں لیکن
آدمی کا کوئی وکیل نہیں

ہے کشادہ ازل سے روئے زمیں
حرم و دیر بے فصیل نہیں

زندگی اپنے روگ سے ہے تباہ
اور درماں کی کچھ سبیل نہیں

تم بہت جاذب و جمیل سہی
زندگی جاذب و جمیل نہیں

مت کرو بحث ہار جاؤ گی
حسن اتنی بڑی دلیل نہیں

"جون ایلیا"
Continue Reading...

Top 50 Linux System Administrator Interview Questions



Summary: Today, the job opportunities for Linux experts are more than ever. The Linux System Administrator interview questions range from basic Linux questions to networking, DevOps, and MySQL questions. So, one needs to prepare adequately to ensure success in the Linux system administrator interview process. 
According to a report, the open source and Linux job market is full of new opportunities. Due to the increasing adoption of open source technologies by the technology giants (Microsoft says HELLO!), there are ample job opportunities for system administrators and DevOps professionals.
While a huge demand continues to exist, just like any other job in the technology world, System Administrator have to go through a rigorous hiring process that consists of preparing a professional resume, technical exams, and interview questions. Out of these, cracking a job interview is often the most critical test.
During an interview, a candidate’s personal qualities are also checked and it’s evaluated if he/she is a right fit for the company. Apart from being calm and composed, being well-prepared for an interview is the best thing one can do in order to crack a Linux System Administrator interview.
             Read: 10 Best password cracking tool of 2016   


If you open your web browser and search for the phrase Linux System Administrator interview questions, you’ll get a long list of search results that will help your practice. Apart from the straightforward conceptual questions like “What does the permission 0750 on a file mean?”, Linux System Administrator interviews also come loaded with expert questions like “How do you catch a Linux signal on a script?”
To help you out in the Linux system administrator  interviews, I’ve compiled a list of my favorite questions of variable difficulty. These questions are framed with different approaches to find out more about the candidate and test his/her problem-solving skills:
1. What does nslookup do?
2. How do you display the top most process utilizing CPU process?
3. How to check all open ports on a Linux machine and block the unused ports?
4. What is Linux? How is it different from UNIX?
5. Explain the boot process of Unix System in details.
6. How do you change the permissions? How to create a file that’s read-only property?
7. Explain SUDO in detail. What are its disadvantages?
8. What is the difference between UDP and TCP?
9. Describe the boot order of a Linux machine.
10. Design a 3-tier web application.
11. Sketch how you would route network traffic from the internet into a few subnets.
12. How do you know about virtualization? Is it good to use?
13. What are different levels of RAID and what level will you use for a web server and database server?
14. List some latest developments in open source technologies.
15. Have you ever contributed to an open source project?
16. Systems engineer or a systems administrator? Explain?
17. List some of the common unethical practices followed by a system professional.
18. What is the common size for a swap partition under a Linux system?
19. What does a nameless directory represent in a Linux system?
20. How to list all files, including hidden ones, in a directory?
21. How to add a new system user without login permissions?
22. Explain a hardlink. What happens when a hardlink is removed?
23. What happens when a sysadmin executes this command: chmod 444 chmod
24. How do you determine the private and public IP addresses of a Linux system?
25. How do you send a mail attachment using bash?
26. Tell me something about the Linux distros used on servers.
27. Explain the process to re-install Grub in Linux in the shortest manner.
28. What is an A record, an NS record, a PTR record, a CNAME record, an MX record?
29. What is a zombie process? State its causes?
30. When do we prefer a script over a compiled program?
31. How to create a simple master/slave cluster?
32. What happens when you delete the source to a symlink?
33. How to restrict an IP so that it may not use the FTP Server?
34. Explain the directory structure of Linux. What contents go in /usr/local?
35. What is git? Explain its structure and working.
36. How would you send an automated email to 100 people at 12:00 AM?
37. Tell me about ZFS file system.
38. How to change the default run level in a Linux system?
39. How would you change the kernel parameters in Linux?
40. State the differences between SSH and Telnet.
41. How would you virtualize a physical Linux machine?
42. Tell me about some quirky Linux commands.
43. Explain how HTTPS works.
44. Do you know about TOR browser? Explain its working.
45. How to trigger a forced system check the next time you boot your machine?
46. What backup techniques do you prefer?
47. Tell me something about SWAP partition.
48. Explain Ping of Death attack.
49. How do you sniff the contents of an IP packet?
50. Which OSI layer is responsible for making sure that the packet reaches its correct destination?


Thank you for Reading
For More visit: https://amadahmad.blogspot.com
Continue Reading...

Become who you are.



"Don't be afraid of yourself, don't be shy, don't be a hypocrite. Take courage and take off your mask, throw away your cloak. Accept your beauty, embrace your ugliness, make peace with yourself and become who you really are".
Continue Reading...

10 Best Password Cracking Tools Of 2016


Password cracking is an integral part of digital forensics and pentesting. Keeping that in mind, we have prepared a list of the top 10 best password cracking tools that are widely used by ethical hackers and cyber-security experts. These tools–including the likes of Aircrack, John the Ripper, and THC Hydra–use different algorithms and protocols to crack the passwords on a Windows, Linux, and OS X system.

W
hat is password cracking?

In the field of cyber-security and cryptography, password cracking plays a very major role. It’s basically the process of recovering passwords to breach (or restore) the security of a computer system. You can easily relate it to repeatedly guessing your phone’s unlock pattern or pin.
So, why do we need to learn about password cracking and the tools used to do so? The purpose of password cracking revolves around recovering the forgotten passwords of our online accounts, computers, and smartphones. Password cracking is also used by system administrators as a preventive measure. They keep checking them on the regular basis to look for the weak links.
Talking about the process of password cracking, most methods involve the use of a computer that generates a vast set of password candidates. A desktop computer tests more than hundreds of millions of passwords per second. A password cracking tool performs this task easily and checks these candidates to reveal the actual password.
The time needed to crack a password is proportional to the length and strength of that password. That’s why users are advised to use complex passwords that are harder to guess. The password cracking speed of a tool also depends heavily on the cryptographic function that’s used to generate password hashes. Thus, a potent hashing function like bcrypt is preferred over the likes of SHA and MD5.

Types of password cracking attacks:

Here’s I’ll be listing various types of password cracking attacks that are generally used by attackers:
  • Dictionary attack: This attack uses a file that contains a list of words that are found in the dictionary. This mode matches different combinations of those words to crack your device open.
  • Brute force attack: Apart from the dictionary words, brute force attack makes use of non-dictionary words too.
  • Rainbow table attack: This attack comes along with pre-computed hashes. Thus, this method is faster.
There are lots of other password cracking techniques like phishing, spidering, social engineering, shoulder surfing etc. Soon, I’ll be discussing them in detail in another article. So, let’s get started with our list of the best password cracking tools of 2016.

Best Password Cracking Tools Of 2016:

Disclaimer: We are publishing this list just for educational purposes. We don’t promote malicious and unethical practices.

1) John the Ripper


John the Ripper is one of the most popular password cracking tools available around. This free password cracking tool is chiefly written in C programming language. Encompassing a customizable password cracker, John the Ripper comes as a combination of many password crackers into one suite.
Its ability to auto-detect password hashtypes, makes it a preferred choice of ethical hackers to ensure security. A pro version of this tool is also available, offering better features and more effectiveness. Just like the popular hacking tool Metasploit, John also belongs to the Raspid7 family of security tools.
Supported platforms: John the Ripper is available for all major platforms, including Linux, Windows, DOS, and OS X.
Download link: John the Ripper

2) Aircrack-ng


Aircrack-ng (ng stands for new generation) is one of the best password cracking tools that hackers use to bump their annoying neighbors off their own Wi-Fi. Note that just like John the Ripper, Aircrack-ng is not a single tool. Instead, it’s a complete software suite that’s used to play with Wi-Fi networks.
In this free suite, you get a tool named aircrack that hackers use to crack WPA or WEP passwords. After analyzing the encrypted password packets, aircrack uses its cracking algorithm to break the passwords.
Using the well know attack techniques like FMS, this password cracking tool makes your job easier. Recently, a new attack named “PTW” has been included in the suite, which reduces the number of initialization vectors to break a WEP key.
Supported platforms: Aircrack is available for Linux, OpenBSD, FreeBSD, OX X, Windows, Android
Download link: Aircrack-ng

3) RainbowCrack


As the name suggests, RainbowCrack makes use of rainbow tables to crack password hashes. Using a large-scale time-memory trade-off, RainbowCrack performs an advance cracking time computation. According to your convenience, you are free to use the command line or graphical interface of RainbowCrack.
Once the pre-computation stage is completed, this top password cracking tool is about hundreds of times faster than a brute force attack. You also don’t need to prepare the rainbow tables yourselves. The developers have made different rainbow tables for LM, NTLM, MD5 and SHA1 available for free.
RainbowCrack’s GPU acceleration is another key feature that allows this free password cracking tool to offload the runtime computation to GPUs, reducing the cracking time even further.
Supported platforms: RainbowCrack is available for Windows and Linux
Download link: RainbowCrack

4) Cain and Abel


This renowned password cracking tool is a dependable software to recover various types of passwords using multiple techniques. Cain and Able lets you easily perform Dictionary, Brute-Force, and Cryptoanalysis attacks to crack encrypted passwords.
This multi-purpose hacking tool also comes with the ability to sniff the networks, record VoIP conversations, recover network keys, decode scrambled passwords, and analyze routing protocols.
Cain and Abel has two components. While Cain is the front-end application to recover your passwords and perform sniffing, Able is a Windows NT service that performs the role of traffic scrambling.
Supported Platforms: Cain and Abel is available for Windows
Download link: Cain and Abel

5) THC Hydra


Compared to other top password cracking tools, THC Hydra performs hacking attacks using numerous network protocols, including the likes of Asterisk, FTP, HTTP-Proxy, MYSQL, XMPP, Telnet, and more. Using these protocols, THC Hydra performs super fast brute-force and dictionary attacks against a login page.
This free-to-use tool helps the pentesters and security researchers to know how easy it would be to gain remote access to a system. This tool also lets you add new modules to increase the functionality. Via its GitHub page, you can also participate in the development process of THC Hydra.
Supported Platforms: THC Hydra is available for Windows, Linux, Solaris, FreeBSD, OS X
Download link: THC Hydra

6) HashCat


HashCat claims to be the fastest and most advanced password cracking software available. Released as a free and open source software, HashCat supports algorithm like MD4, MD5, Microsoft LM hashes, SHA-family, MySQL, Cisco PIX, and Unix Crypt formats.
This password cracking tool comes in both CPU-based and GPU-based versions, HashCat and oclHashcat/cudaHashcat, respectively. Using a well-documented GPU acceleration, many algorithms can be easily cracked using this tool.
Different types of attacks performed by this tool include brute force attack, combinator attack, fingerprint attack, dictionary attack, hybrid attack, mask attack, table-lookup attack, PRINCE attack, permutation attack etc.
Supported Platforms: HashCat is available for Windows, Linux, OS X
Download link: HashCat

7) Crowbar


Crowbar is a brute forcing tool that’s widely popular in the pen testing scene. It gives you the control to decide what’s submitted to a web server. While most brute forcing tools use username and password to deploy SSH brute force, Crowbar makes use of SSH keys obtained during penetration tests.
This free tool is created to support the protocols that are rarely supported by other popular password cracking tools. Currently, Crowbar supports VNC key authentication, OpenVPN, SSP private key authentication, and Remote Desktop Protocol with NLA support.
Supported Platforms: Crowbar is available for Windows, Linux, OS X
Download link: Crowbar

8) OphCrack



Just like RainbowCrack, OphCrack is another popular and free password cracking tool that uses rainbow tables to crack the password hashes. It’s widely used to crack Windows log-in passwords. Thanks to its ability to import and use hashes from multiple formats and sources, OphCrack is known to crack the passwords of a Windows computer in few minutes.
Available conveniently as a Live CD, a pentester can use it and leave no trace behind. For cracking Windows XP, Vista, and 7, one can also grab freely available rainbow tables. For professional use, larger tables are available for purchase.
Supported Platforms: OphCrack is available for Windows
Download link: OphCrack

9) L0phtCrack


Just like OphCrack, L0phtCrack is known for easily cracking Windows passwords. Using a wide set of attacks like dictionary, hybrid, brute force, and rainbow tables, this password cracking tool can also be deemed useful in sniffing hashes.
It’s a great way to target Windows desktops, networked servers, Active Directory, and primary domain controllers. Its schedule routine audit functionality lets you perform scans at a convenient time.
Supported Platforms: L0phtCrack is available for Windows
Download link: L0phtCrack

10) DaveGrohl


For Mac OS X, DaveGrohl is an open source password cracking tool that’s preferred by the Apple security experts. With a completely modern object-oriented codebase in Version 3.0, DaveGrohl has been made more useful for developers and users.
With the help of dictionary and incremental attacks, this tool lets you crack a password in minutes. Its distributed mode allows you to perform attacks using different computers and crack the same password hash for faster results.
Supported Platforms: DaveGrohl is available for OS X
Download link: DaveGrohl
Thank you for Reading
For latest visit: https://amadahmad.blogspot.com
Continue Reading...

Everyone wants the truth, But no one want to be honest.

Amad Ahmad
Continue Reading...
Subscribe to: Posts ( Atom )