web-security-1215757214755670-9.pdf

Web Security
Secure yourself on the web

What is web security?
Almost everything relies on computers and
the Internet now
- communication (email, cell phones)
- transportation (car engine systems)
airplane navigation )
- medicine (equipment, medical records)
- shopping (online stores, credit cards)
- entertainment (digital cable, mp3s)

What is web security?
(contd…)
Web Security, also known as “Cyber
security” involves protecting that
information by preventing, detecting, and
responding to attacks.

What can Web users do?
The first step in protecting yourself is to
recognize the risks and become familiar
with some of the terminology associated
with them.

Web Security: Terminologies
 Hacker – people who seek to exploit
weaknesses in software and computer
systems for their own gain.
 Viruses – It you to actually do something
before it infects your computer. This action
could be opening an email attachment or
going to a particular web page.

 Worms - Worms propagate without user
intervention. Once the victim computer
has been infected the worm will attempt to
find and infect other computers.
 Trojan horses - A Trojan horse program
is software that claims to be one thing
while in fact doing something different
behind the scenes.

Ransomware
 A form of trojan that has been around since
1989 (as the “PC CYBORG” trojan)
 It infects the target computer by encrypting the
owner's personal files.
 The victim is then contacted and offered a key
to decrypt the files in exchange for cash

KeyLoggers:
 Traditionally, Keyloggers are software that
monitor user activity such as keys typed using
keyboard.
Modern keyloggers can,
 Record keystrokes on keyboard
 Record mouse movement and clicks
 Record menus that are invoked
 Take screenshots of the desktop at predefined
intervals (like 1 screenshot every second)

KeyLoggers: (contd…)
Such recorded data could be uploaded in real-time
or when internet connection becomes available,
by,
 Email attachment
 IRC Channel
 File Transfer (FTP)

KeyLoggers: (contd…)
Keylogger prevention
 Use Anti-Spyware (prevention)
 Firewall (manual detection)
 Automatic Form fillers (protection from keylogging)
In public (insecure) places,
-use on-screen keyboards
(START-> ALL PROGRAMS ->ACCESSORIES ->
ACCESSIBILTY ->ON-SCREEN KEYBOARD)

Firewalls:
Mechanism for content regulation and data filtering
 Blocking unwanted traffic from entering the sub-
network (inbound)
 Preventing subnet users' use of unauthorised
material/sites (outbound)

Aspects of data Security
 Privacy
 Keeping your information private
 Integrity
 Knowing that the information has not been changed
 Authenticity
 Knowing who sent the information

Privacy
 Your personal details are a valuable asset
 Businesses are increasingly looking to
target individuals more effectively, data
about those individuals is in demand
 Buying and selling lists of email addresses
and demographic details is big business

Integrity
 Maintaining the data integrity of any
communication is vital.
 Integrity can be preserved by using strong
encryption methods.
 Even if an intruder see the transmission, it
would be useless since its encrypted.

Authentication
We need to authenticate a message to
make sure it was sent by the correct
person.
- Digital signature is used for the purpose
- Public key , Private key method can also
be used to authenticate.

Authentication , Continued…
Most of us use webmail for email handling.
This simple code can send an email,
<? php
mail(“recipient@yahoo.com”, ”Hi from Bill Gates”, ”Hi, I am
Bill gates” , "From: billgates@microsoft.com");
?>

Received email:
From: billgates@microsoft.com
To: recipient@yahoo.com
Subject: Hi from Bill Gates
Hi, I am Bill gates

 So, anyone can send email from anyone’s
email address
 Its possible due to the nature of SMTP
protocol
 Yahoo! has implemented DomainKeys, a
method to authenticate that an email
originated from the sender’s domain.

Web Security Issues
 Malicious websites
 SPAM
 419 Scams
 Phishing
 DDOS
 Botnets
(All aspects are inter-related)

Malicious websites
 More than 3 million Web pages on the Internet are malicious.
 According to Neils Provos, senior staff software engineer with
Google, the percent is one in 1,000.
 The experts call these attacks "drive-by downloads"
Malicious websites
China - 67%
US - 15%
Russia - 4%
Malaysia - 2.2%
Korea - 2%

Malicious websites
Preventive measures
- Use latest browser software
- Internet Explorer version 7+
- Mozilla Firefox
- Opera
Internet Explorer 6 is the most vulnerable as
well as the most widely used browser.
It is highly recommended to upgrade from IE 6

SPAM
Spam is unsolicited e-mail on the Internet.
Spam detection algorithms
 White listing
 Black listing
 Training based algorithms

SPAM
Cost of spam
 Loss of productivity is the main concern
 There is also the cost of bandwidth taken
by spam
 Storage and network infrastructure costs.
 Loss of legitimate email messages

SPAM
- Corporate employees are
reported to accrue a loss of
productivity of 3.1%. - Nucleus
Research Analysis
- To increase the effectiveness
of SPAM detection, always
report any SPAM mail to your
SPAM filter.

419 Nigerian Scams
An advance fee fraud is a confidence trick
in which the target is persuaded to
advance sums of money in the hope of
realizing a very much larger gain
The number "419" refers to the article of the
Nigerian Criminal Code (“Cheating")
dealing with fraud.

419 Nigerian Scams
A sample 419 Scam email
-------------------------------------
Sender: uk_national_lottery_005@hotmail.com
Subject: !!!CONGRATULATIONS YOU ARE A WINNER!!!
FROM THE LOTTERY PROMOTIONS MANAGER,
THE UNITED KINGDOM INTERNATIONAL LOTTERY,
PO BOX 287, WATFORD WD18 9TT,
UNITED KINGDOM.
We are delighted to inform you of your prize release from the United Kingdom
International Lottery program. Your name was attached to Ticket number;
47061725, Batch number; 7056490902, Winning number; 07-14-24-37-43-48 bonus
number 29, which consequently won the lottery in the first category....
-------------------------------------------

419 Nigerian Scams
The email asks to send an advance
payment to the lottery so that they can
release the prize money.
Lots of naive users get fooled by the
scammers and end up wasting their
money.

419 Nigerian Scams
Prevention:
Awareness is the only tool against such
scammers.
Services like 419eater.com has users who
pretend to be naive and end up wasting
the scammer’s efforts.

Phishing
This is a method of luring an unsuspecting
user into giving out their username and
password for a secure web resource,
usually a bank or credit card account.

Phishing
 Usually achieved by creating a website identical to the
secure site
 User is sent email requesting them to log in, and providing
a link to the bogus site
 When user logs in, password is stored and used to access
the account by the attacker
 Difficult to guard against, particularly if using HTML email

Phishing
Phishing Email sample:
Subject: Verify your E-mail with Citibank
This email was sent by the Citibank server to verify your E-mail
address. You must complete this process by clicking on the link
below and entering in the small window your Citibank ATM/Debit
Card number and PIN that you use on ATM.
This is done for your protection - because some of our members
no longer have access to their email addresses and we must
verify it.
To verify your E-mail address and access your bank account,
click on the link below:
https://web.da-us.citibank.com/signin/citifi/scripts/email_verify.jsp
Thank you for using Citibank

Phishing
Instead of,
http://www.citibank.com/us/index.htm
The link uses an anchor text, and the
actual website opens as,
http://citibusinessonline.da.us.citibank.com.citionline.ru/...

Phishing
- Unwitting users submit the data, and the
data is captured by scammers and all the
money in their account will be stolen
immediately.
- This method is the main reason for loss of
email passwords also.

Denial of Service
It is an attack to make a computer resource
unavailable to its intended users.
Resources:
- Bandwidth & CPU

Distributed DOS
A powerful variant of DOS attack.
-Web server can handle a few hundred
connections/sec before performance
begins to degrade
-Web servers fail almost instantly under five
or six thousand connections/sec

Distributed DOS
- Zombie system is a system that is brought
under the attacker’s control by using
virus/worm/exploits.
- Attack is initiated using compromised
Zombie systems.
- Very hard to prevent, since large number
of zombie systems will be used.

Botnets
A botnet is a collection of compromised
computers (called zombie computers)
running programs
- Usually installed via worms, Trojan
horses, or backdoors,
- Under a common command and control
infrastructure.

Botnets
Botnet
Admin
Bot
Spammer

Botnets
1.A botnet operator sends out viruses or worms, infecting
ordinary users' computers, whose payload is a malicious
application -- the bot.
2.The bot on the infected PC logs into a particular IRC
server (or in some cases a web server). That server is
known as the command-and-control server (C&C).
3.A spammer purchases access to the botnet from the
operator.
4.The spammer sends instructions via the IRC server to the
infected PCs causing them to send out spam messages to
mail servers.

Botnets
 A botnet's originator (aka "bot herder") can
control the group remotely, usually through a
means such as IRC.
 A botnet is more power than a supercomputer in
terms of its processing capacity.
 As of 2007, the average size of a botnet was
estimated at 20,000 computers, although larger
networks continued to operate.

Botnet Case Study
STORM BOTNET
 The Storm botnet is a remotely-controlled
network of "zombie" computers (or "botnet") that
has been linked by the Storm Worm, a Trojan
horse spread through e-mail spam.
 Sources have placed the size of the Storm
botnet to be around 250,000 to 1 million
compromised systems.

Botnet Case Study
STORM BOTNET
 Detected in January 2007
 1.2 billion virus messages have been sent by
the botnet till September 2007
 The Storm botnet has been used in a variety of
criminal activities.
 Its controllers, and the authors of the Storm
Worm, have not yet been identified.

Botnet Case Study
STORM BOTNET
 The botnet has specifically attacked the online operations
of some security vendors and researchers who attempted
to investigate the botnet
 The botnet reportedly is powerful enough as of September
2007 to force entire countries off the Internet,
 The Storm botnet's operators control the system via peer-
to-peer techniques, making external monitoring and
disabling of the system more difficult
 There is no central "command-and-control point" in the
Storm botnet that can be shut down

Botnet Case Study
STORM BOTNET
Action plan:
 Microsoft update to the Windows Malicious Software Removal Tool (MSRT)
may have helped reduce the size of the botnet by up to 20%.
 But, most of the Windows systems are not configured for Automatic
updates.
 Consider our country as example, where most home users use pirated
copies of windows.
 Pirated copies will get disabled when updated online,becasue of Windows
Genuine Advantage (WGA) program.

More Botnets
Name Size Spam sent / day
SRIZBO 315,000 60 billion
BOBAX 185,000 9 billion
RUSTOCK 150,000 30 billion
CUTWAIL 125,000 16 billion
GRUM 50,000 2 billion
OZDOK 35,000 10 billion
NUCRYPT 20,000 5 billion
WOPLA 20,000 600 million
SPAMTHRU 12,000 350 million

Botnet Attacks
Example 1:
Cyber Assault on Estonia
Estonia is a small and one of the most
internet enabled country in Europe.

Botnet Attacks
Example 1:
It was attacked by a massive DDOS attempt on May 2007.
Attacked sectors include
 government
 banks
 telecommunications companies
 Internet service providers
 news organizations

Botnet Attacks
Example 1:
 Attack effectively shut down email systems and online
banking.
 Attack originated from Russia after Russian govt got
angry with Estonia for relocating a Soviet war memorial.
 More than a million zombie computers made the attack
possible.

Botnet Attacks
Example 2: April 23, 2008
 Slideshare is a service that lets you upload and embed
PowerPoint presentations on the web.
 There were several presentations relating to corruption in
the chinese government.
 Chinese authorities requested those slides to be removed.

Botnet Attacks
Example 2: April 23, 2008
 Slideshare was down for a few days due to DDOS attack
that originated from China.
 The attack reached a peak of 2.5GB/sec and consisted
entirely of packets sent from China
 SlideShare insiststhat it will do everything it can to protect
its users’ freedom of speech. As such, it has no plans to
remove any of the content in question.

Botnet Attacks
In both examples, botnets were the main
attack vehicles.
There are several more examples.
So,
Cyber wars <= DDOS <=Botnets <=Virus/Worm <= Ignorant web user

Take Action
If everyone keep their systems secure, such
threats can never happen.
Small gestures can avoid gigantic problems
in our context.

Action Plan
 Use Anti-virus
 Use Anti-Spyware
 Be aware not to fall for scams and
phishing attacks
 Report SPAM

Further Action
 www.419eater.com
 www.antiphishing.org

Web Security
This presentation can be downloaded from
www.bharath.name
For any queries or doubts or help,
bharath@bharath.name

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