Introduction

The Information Security Field

⚡ Penetration Testing Usage:

• Knowing the information security (infosec) field

• Career opportunities

• Talking with colleagues

InfoSec Culture

Deep roots in the underground hacking scene.

Hacker = refers to people who prefer to understand how a system works, being curious, intelligent and motivated to pursue knowledge.

Usually a hacker approaches systems with curiosity, so he can:

• Find new ways to use computer systems

• Bypass imposed restrictions

• Understand security pitfalls

Performing an attack means to understand the technology and the functioning of the target system.

Being a Hacker means improving skills every day, pushed by curiosity and hunger for knowledge.

📕 There is always something new to learn! Hacking is a lifestyle.

Being an InfoSec professional means pursuing knowledge by keeping challenging yourself and your colleagues, being honest with yourself and never stop.

• To have an idea about the ideals of the underground hacking community read The Conscience of a Hacker.

Career Opportunities

Companies and government bodies are using advanced tech to store and process confidential data. Using hacking skills for good has become critical for the safety of nations too.

Data is transmitted across private & public networks. It is a must to:

• Protect sensitive information

• Implement hardware and software defensive systems

• Protect digital assets from major cyber-threats like:

  • global cyber syndicates

  • hackers for hire

  • hacktivists

  • terrorists

  • state-sponsored hackers

Train the organization to make sure:

• secure applications are developed

• proper defensive measures are taken

• proper use of the company's data is in place

Hire a penetration tester to ensure that a system is secure from cyber-attacks.

Penetration Testers (a.k.a. pentesters) = are professionals hired to simulate a hacking attack against a network, a computer system, a web application or the entire organization. They discover vulnerabilities across the tested systems by mastering the same tools and techniques used by malicious hackers. They often work:

• as freelancers

• in an IT Security services company

• as in-house employees

Pentesters can specialize in specific InfoSec sectors:

• Systems attacks

• Web Applications

• Malware Analysis

• Reverse Engineering

• Mobile Applications

• Network Pentesting

• Social Engineering

• Other...

📌 Be passionate, skilled and hungry for knowledge!

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Information Security Terms

It is fundamental to speak the InfoSec domain language.

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WHITE HAT HACKER

• is a professional pentester or ethical hacker who performs authorized attacks against a system helping the client solve their security issues.

• they do NOT perform illegal actions.

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BLACK HAT HACKER

• is a hacker who performs unauthorized attacks against a system with the purpose of causing damage or gaining profit.

• a category of black hat hackers is called "crackers".

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USER

• is a computer system user (an employee of your client of an external user).

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MALICIOUS USER

• is a user who misuses or attacks computer systems and applications.

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ROOT / ADMINISTRATOR

• are the users who manage IT networks or single systems.

• they have maximum privileges over a system.

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PRIVILEGES

• identify the action that a user is allowed to do.

• the higher the privileges, the more control.

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SECURITY THROUGH OBSCURITY

• is the use of secrecy of design, implementation or configuration in order to provide security.

• it cannot stop a skilled and motivated attacker.

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ATTACK

• is any kind of action aimed at misusing or taking control over a computer system or application.

  • unauthorized access to an administration area

  • stealing a user's credentials

  • causing denial of service

  • eavesdropping or communications

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PRIVILEGE ESCALATION

• privesc is an attack where a malicious user gains elevated privileges over a system.

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DENIAL OF SERVICE

• a DoS attack is used by an attacker to make a system or a service unavailable / unresponsive, causing a service crash or resources saturation.

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REMOTE CODE EXECUTION

• during a RCE attack a malicious user executes some attacker-controlled code on a victim remote machine.

• RCE vulnerabilities can be exploited over the network by a remote attacker.

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SHELL CODE

• is a piece of custom code which provides the attacker a shell on the victim machine, generally used during RCE attacks.

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Cryptography Protocols & VPNs

⚡ P.T. Usage:

• Knowing how info is transmitted over networks, by using the right protocol for the transmission

• Traffic protection

Clear-text Protocols

• They should not be used for the transmission of critical or private info, since it's easy to intercept.

• Use clear-text protocols only on trusted networks, if really necessary.

Cryptographic Protocols

• They are used to protect the communication by encrypting the transmitted information, in case of eavesdropping.

• Always use a cryptographic protocol for usernames and passwords.

A Clear-text protocol information can be wrapped into a cryptographic protocol, like a VPN tunnel.

Virtual Private Networks (VPN)

A VPN establish a secure, encrypted and protected connection between a private network and a public one (or the Internet), using a private tunnel for the data.

• The client is directly connected to the private network.

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Wireshark

• Wireshark is a network sniffer tool and packet analyzer, that allows to capture the data transmitted over the network.

🔬 Check HTTP(s) Traffic Sniffing lab.

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Binary Arithmetic Basics

⚡ P.T. Usage:

• Computer/Boolean logic, data is represented in binary format

• Network addressing

Binary and Decimal Bases

Binary notation uses only two symbols to represent numbers, 0 (zero) and 1 (one).

Decimal notation uses ten symbols (0 to 9).

• Counting in binary: start counting from 0, when reach 1, you increment the digit to the left of it.

  • 0, 1, 10, 11, 100, 101, 110, 111, 1000 ... and so on.

• Converting from binary to decimal: by using the position of the digits.

  $$11011(_2) = 1*2^0+1*2^1+0*2^2+1*2^3+1*2^4=27_{(10)}$$
• Converting from decimal to binary:

  • by dividing the decimal number by 2 (base 2), write the remainder, continue like this until reaching 0 as dividend.

  $$26/2=13 \\remainder\ is\ 0 \\ 13/2=6 \\remainder\ is\ 1 \\ 6/2=3 \\remainder\ is\ 0 \\ 3/2=1 \\remainder\ is\ 1 \\ 1/2=0 \\remainder\ is\ 1 \\$$

  $$26_{(10)}=11010(_2)$$

  • Or use the powers of two in a "base 2 table":

  $${Powers\ of\ 2} \\ 2^0=1 \\ 2^1=2 \\ 2^2=4 \\ 2^3=8 \\ 2^4=16 \\ 2^5=32 \\ 2^6=64 \\ 2^7=128 \\ 2^8=256 \\ 2^9=512 \\ 2^{10}=1024 \\ 2^{11}=2048 \\ 2^{12}=4096 \\ 2^{13}=8192 \\ 2^{14}=16384 \\ 2^{15}=32768$$

  $${Example\ } \\ 2^4+2^3+2^1=16+8+2=26 \\ 2^4\ YES\ \dashrightarrow 1 \\ 2^3\ YES\ \dashrightarrow 1 \\ 2^2\ NO\ \dashrightarrow 0 \\ 2^1\ YES\ \dashrightarrow 1 \\ 2^0\ NO\ \dashrightarrow 0 \\ 26_{(10)}=11010(_2)$$

Bitwise operations

• NOT flips the bits - zero to one, and one to zero.

  $$NOT(11011)=00100$$
• AND logical AND (&) between the bits of the operands.

  $${If\ both\ bits\ are\ =1, result\ is\ 1.} \\ 0\ \&\ 0\ = 0 \\ 0\ \&\ 1\ = 0 \\ 1\ \&\ 0\ = 0 \\ 1\ \&\ 1\ = 1$$

  $$1010\ \&\ 1101\ = 1000$$
• OR logical OR (|) between the bits of the operands.

  $${If\ at\ least\ one\ bit\ is\ =1, result\ is\ 1.} \\ 0\ |\ 0\ = 0 \\ 0\ |\ 1\ = 1 \\ 1\ |\ 0\ = 1 \\ 1\ |\ 1\ = 1$$

  $$1010\ |\ 1100\ = 1110$$
• XOR logical Exclusive OR (^ , ⊕) between the bits of the operands.

  $${If\ just\ one\ bit\ is\ =1, result\ is\ 1.} \\ 0 \oplus 0\ = 0 \\ 0 \oplus 1\ = 1 \\ 1 \oplus 0\ = 1 \\ 1 \oplus 1\ = 0$$

  $$1010 \oplus 1101\ = 0111 = 111$$

Windows calculator can help with calculations in "Programmer" mode.

Hexadecimal arithmetic

Hexadecimal system is used too in computer science. It uses 16 symbols (with letters for double-digit numbers):

• 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F

To distinguish a hexadecimal number from a decimal number, "0x" at the beginning or "h" at the end is added.

• Converting from hexadecimal to decimal: by using the position of the digits.

  $$0x4a1 = 0x(4\ 10\ 1) \\ 0x4a1 = 1*16^0 + 10*16^1 + 4*16^2 = 1 + 160 + 1024 = 1185_{(10)}$$
• Converting from decimal to hexadecimal:

  • by subsequently dividing the decimal number by 16 (base 16), write the remainder, continue like this until reaching 0.

  $$1185/16=74,0625 \\remainder\ is\ 0,0625 \\ 74/16=4,625 \\remainder\ is\ 0,625 \\ 4/16=0,25 \\remainder\ is\ 0,25 \\ 0/16=can't\ divide\ 0.$$

  $$0.25*16=4 \\ 0.625*16=10\ (a) \\ 0.0625*16=1$$

  $$1185_{(10)}=4a1_{(16)}=0x4a1$$

📌Online converters can help to speed up the calculations, for example here you can find some conversion tools Binary Hex Converters.

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