Botnets are networks of compromised computers called zombies or bots that are controlled remotely by an attacker known as a bot herder. Originally bots were useful tools but now are used for malicious purposes. A botnet has four main components: the bot herder who installs bot software on vulnerable systems, the bots or zombies, an IRC server for communication, and a command and control server to issue instructions. The bot herder builds their botnet army by infecting home and small business computers. Once installed, bots communicate secretly with the C&C server to receive tasks like DDoS attacks, spamming, phishing and stealing information.

1. BOTNETS
By: Sumit Saurav [Dev Sanskriti University]

2. CONTENTS
Bot Herder (Bot Master), IRC Server,
Command & Control Server(C&C)
Botnet Terminology
03
How Botnets Started To Emerge?
History
02
Life A Botnet
Botnet Life Cycle
04
Which Types Of Attacks Are
Performed By Botnets
Types Of Attacks
05
What are Botnets?
Introduction
01

3. BOTNETS
A Botnet is a network of compromised computers called
Zombie Computers or Bots, under the control of a remote
attacker.
Bots began as a useful tool. They were originally
developed as a virtual individual that could sit on a IRC
channel & monitor network traffic.
They are significant contributors to the malicious &
criminal activities on the Internet today and far importantly
an underground network whose size & scope is not fully
known.

4. HISTORY
• In the beginning, there were only good bots.
• ex: google bot, game bot etc.
• Later, bad people thought of creating bad bots so that
they may
• Send Spam and Phishing emails
• Control others pc
• Launch attacks to servers (DDOS)
• Many malicious bots were created
• SDBot/Agobot/Phatbot etc.
• Botnets started to emerge

5. BASIC TERMINOLOGIES
 Bot Herder(Bot Master)
 Bots
 IRC Server
 Command & Control Server (C&C)

6. BOT HERDER
 Bot herders(aka Bot Masters)are the hackers who use
automated techniques to scan specific network ranges and
find vulnerable systems, on which they can install their
bot program.
 To create an army of Zombies over internet, attacker
typically infect machines of home users, network
maintained by universities or small enterprises, etc.

7. Bots
 Bots (also called Zombie Computers)are the
computers that contribute to the botnet network.
 They run using a hidden channel to communicate
to their C&C server.
 They can auto scan their environments and
of
propagate themselves taking advantage
vulnerabilities &weak passwords.

8.  IRC Server
 Internet Relay Chat (IRC) is a form of real-time Internet
text messaging (chat).
 The server listens to connections from IRC clients enabling
people to talk to each other via the Internet.
 Most IRC servers do not require users to register an account
but a user will have to set a nickname before being
connected.
 Most IRC networks lack any strong authentication, and a
number of tools to provide anonymity on IRC networks are
available.
 IRC provides a simple, low-latency, widely available, and
anonymous command and control channel for botnet
communication.

9. Command & Control Server
 C&C infrastructure allows a bot agent to receive new
instructions, malicious capabilities, update existing
infections or to instruct the infected computer to carry out
specific task as dictated by the remote controller.
 The criminal actively controlling botnets must ensure that
their C&C infrastructure is sufficiently robust to manage
tens-of-thousands of globally scattered bots as well as resist
attempts to hijack or shutdown the botnet.

10. Bot Master
Bots
IRC Server
Victim
IRC Channel
Attack
IRC Channel
C&C Traffic
BOTNET LIFE CYCLE

15. TYPES OF ATTACKS
 Distributed Denial of Service (DDoS)
attacks
 Sending Spams
 Phishing (fake websites)
 Adware
 Spyware (keylogging, information
harvesting)
 Click Fraud

16. REFERENCES
 Adam J.Aviv,Andreas Haeberlen. Challenges in
Experimenting with Botnet Detection
Systems.2011.
 March 2011 Intelligence Report. Symantec.
Cloud.
 Paul Bacher, Thorsten Holz, Markus Kotter,
Georg Wicherski. Know your Enemy: Tracking
Botnets. Technical Report, The Honeynet
Project.Aug 2008.

17. THANK YOU