Transcript Trojan horse

Level 2 Diploma
Unit 11 IT Security
 Covered
last week
• Weak external security
• Unauthorised uses
• Unauthorised removal or copying
 This
week
• Malware
• Theft or loss
• Poor folder and file permissions
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Malware - short for malicious software
a variety of forms of hostile, intrusive, or annoying
software or program code
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Virus
Worm
Trojan horse
Rootkit
Backdoor
Spyware
Botnet
Keystroke logger
Dialer
Adware
 Started
as experiments or pranks, such as
the Melissa virus
 Then changed to destroy files on a hard
disk
 Worms vandalised web pages
 Originally spread on diskettes or in Word
documents
 Released
26th March 1999
 Used stolen e-mail address
 Caused $80 million dollars damage
 E-mailed itself to 1st fifty addresses
‘Outlook’ with attachment such as list.doc
 Looked like e-mail from known associate
 Opened document infected normal.dot
template
 Sent
document from your pc – data security
breach, damage to trust, e-mail delays, cost of
removal
 When the day number equals the number of
minutes in the current time (e.g., at 11:06 on the
6th day of the month), the Melissa virus inserted
the following text in whatever document was
then being edited in Word on the victim's
computer: Twenty-two points, plus triple-wordscore, plus fifty points for using all my letters.
Game's over. I'm outta here.
 Given
Internet access, malicious software
is now designed for a profit
• take control of users' computers for black-
market exploitation
• Infected "zombie computers" are used to
 send email spam,
 to host contraband data such as child pornography
 engage in distributed denial-of-service attacks as a
form of extortion
 Spyware
programs
• monitor a users' web browsing
 display unsolicited advertisements
 redirect money or advertising revenue to
the spyware creator
• Spyware programs do not spread like viruses
• they are installed by
 exploiting security holes
 or are packaged with user-installed software, such as
peer-to-peer applications
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Give a definition and example of one of the
following:
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Virus
Worm
Trojan horse
Rootkit
Backdoor
Spyware
Botnet
Keystroke logger
Dialler
Adware
Phishing
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Virus
• a program that has infected some executable software
and, when run, causes the virus to spread to other executables.
• Viruses may contain a payload that performs other actions,
often malicious.
• A virus requires a user to trigger it spreading
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Worm
• a program that actively transmits itself over a network to infect
other computers.
• It may carry a payload
• It does not require a user to do anything
 Concealment
helps get the malware installed
 When a malicious program is disguised as
something innocuous or desirable, users may
be tempted to install it without knowing what it
does.
 Typical e-mail subject: "This is The Free
Download Sex Movies, you can find it Here"
 This is the technique of the Trojan
horse or Trojan.
 Torpig
• affects Windows, turning off anti-virus
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applications.
allows access to the computer
modifies data
steals confidential information (such as user
passwords and other sensitive data)
installs more malware on the victim's computer
has stolen the details of about 500,000 online
bank accounts and credit and debit cards
 Once
malware is installed, it needs to
remain concealed
 A rootkit:
• Modifies the operating system kernel
• Makes itself invisible in the task and process lists
• May use the name of legitimate files
• Makes its own files unreadable
• Can run copies of itself and restart them if they
are stopped
A
backdoor is
• a method of bypassing normal authentication
• malware can install one or more backdoors
• allows easier access in the future for
 Installation of more malware
 Collecting saved key logger data
 Triggering spam attacks
 Spyware
collects small pieces of information
about users without their knowledge
 Spyware programs can
• collect Internet surfing habits
• collect sites that have been visited
• install additional software
• redirect Web browsers
• change computer settings, resulting in
 slow connection speeds
 different home pages
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collection of compromised computers
(called zombie computers)
 installed via worms, Trojans or backdoors
 remotely controlled
 botnets are rented out to
• send out spam messages
• perform denial of service attacks
• billions of messages can be created per day
 Hardware
• Connected between keyboard and PC
• Can be wirelessly interrogated
 Software
• Malware based
• Captures passwords, form submissions,
clipboard, screen shots
• Transmit data to web sites, e-mail or wireless
 diallers
connect non-broadband PCs
 fraudulent diallers connect to premiumrate numbers
 some diallers promise special content,
such as:
• software for download (usually illegal)
• trojans posing as MP3s
• trojans posing as pornography,
• programs such as cracks and keygens
 Software
which automatically plays,
displays, or downloads advertisements to
a computer
 Some adware can be classified
as spyware e.g. BonziBUDDY
• corrupted many of the user's system files
• displayed obscene advertisements
• logged browsing details and sent them to
various third parties
 Devices
and data which are easily lost or
stolen
• Laptops
• Mobile phones
• USB drives and smart cards (flash memory)
• CDs and DVDs
 Failing
to apply security patches
• Automatic update turned off
• Especially important for
 Operating systems
 Browsers
 complexity
increases the probability of
operating system design flaws
 default permissions grant every program and
every user full access to the entire system
 exploitable bugs in a software program
 unchecked user input can allow unintended
direct execution of commands or SQL
statements
 You
have been put in charge of the
security of the computing department’s
IT systems
 You have been asked to write a report
• Describe the potential security threats that might
damage the system and compromise its data
(P1)
• Evaluate which of these threats are the most
likely to occur and give your reasons (M1)
• Explain what the impact of these threats would
be on the users of the system (D1)