Final malacious softwares


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Final malacious softwares

  1. 1. Presented By: Mirza Adnan Baig Naheed Afzal Aamir Husnain
  2. 2.  Software deliberately designed to harm computer systems.  Malicious software program causes undesired actions in information systems.  Spreads from one system to another through: 1. E-mail (through attachments) 2. Infected floppy disks 3. Downloading / Exchanging of corrupted files 4. Embedded into computer games
  3. 3. Malicious Software Viruses Trapdoor WormsSpywareTrojan HorseHoaxesRabbit Time Bomb Logic BombBoot Viruses File Viruses
  4. 4. These are the programs that spread to other software in the system .i.e., program that incorporates copies of itself into other programs. Two major categories of viruses: 1. Boot sector virus : infect boot sector of systems. become resident. activate while booting machine 2. File virus : infects program files. activates when program is run.
  5. 5.  Dormant phase - the virus is idle  Propagation phase - the virus places an identical copy of itself into other programs  Triggering phase – the virus is activated to perform the function for which it was intended  Execution phase – the function is performed Henric Johnson 6
  6. 6. Polymorphic Virus  Produces modified & fully operational code.  Produces new & different code every time when virus is copied & transmitted to a new host.  Difficult to detect & remove. Stealth Virus  Programming tricks make the tracing and understanding the code difficult.  Complex programming methods used to design code, so difficult to repair infected file. Armored Virus  Hides modifications it has made to files or to the disk.  Reports false values to programs as they read files or data from storage media. Companion Virus  Creates new program instead of modifying existing program.  Contains all virus code.  Executed by shell, instead of original program.
  7. 7. Identifying Viruses :  A virus is a unique program.  It as a unique object code.  The pattern of object code and where it is inserted provides a signature to the virus program.  This virus signature can be used by virus scanners to identify and detect a particular virus.  Some viruses try to hide or alter their signature:  Random patterns in meaningless places.  Self modifying code – metamorphic, polymorphic viruses.  Encrypt the code, change the key frequently.
  8. 8. Effect of Virus attack on computer system  Virus may affect user’s data in memory – overwriting.  Virus may affect user’s program – overwriting.  Virus may also overwrite system’s data or programs – corrupting it – disrupts normal operation of system.  “Smashing the Stack” – Buffer overflow due to execution of program directed to virus code.
  9. 9.  prevention - ideal solution but difficult  realistically need: ◦ detection ◦ identification ◦ removal  if detect but can’t identify or remove, must discard and replace infected program
  10. 10.  virus & antivirus tech have both evolved  early viruses simple code, easily removed  as become more complex, so must the countermeasures  generations first - signature scanners second - heuristics third - identify actions fourth - combination packages
  11. 11.  runs executable files through GD scanner: CPU emulator to interpret instructions virus scanner to check known virus signatures emulation control module to manage process  lets virus decrypt itself in interpreter  periodically scan for virus signatures  issue is long to interpret and scan tradeoff chance of detection vs time delay
  12. 12.  Rabbit : This malicious software replicates itself without limits. Depletes some or all the system’s resources.  Re-attacks the infected systems – difficult recovery.  Exhausts all the system’s resources such as CPU time, memory, disk space.  Depletion of resources thus denying user access to those resources.
  13. 13.  Hoaxes : False alerts of spreading viruses.  e.g., sending chain letters.  message seems to be important to recipient, forwards it to other users – becomes a chain.  Exchanging large number of messages (in chain) floods the network resources – bandwidth wastage.  Blocks the systems on network – access denied due to heavy network traffic.
  14. 14.  A Trojan horse (or Trojan) is a malware program that appears to perform some useful task, but which also does something with negative consequences (e.g., launches a keylogger).  Trojan horses can be installed as part of the payload of other malware but are often installed by a user or administrator, either deliberately or accidentally. 6/13/2014Malware 16
  15. 15.  Time Bomb  Logic Bomb
  16. 16.  A "time bomb" is simply a Trojan horse set to trigger at a particular time/date.
  17. 17.  one of oldest types of malicious software  code embedded in legitimate program  activated when specified conditions met ◦ eg presence/absence of some file ◦ particular date/time ◦ particular user  when triggered typically damage system ◦ modify/delete files/disks, halt machine, etc
  18. 18.  Trojans currently have largest infection potential ◦ Often exploit browser vulnerabilities ◦ Typically used to download other malware in multi-stage attacks 6/13/2014Malware 20 Source: Symantec Internet Security Threat Report, April 2009
  19. 19. 1. Remote access Trojan takes full control of your system and passes it to the hacker. 2. The data-sending Trojan sends data back to the hacker by means of e-mail. e.g., Key-loggers – log and transmit each keystroke.
  20. 20. 3. The destructive Trojan has only one purpose: to destroy and delete files. Unlikely to be detected by anti-virus software. 4. The denial-of-service (DOS) attack Trojans combines computing power of all computers/systems it infects to launch an attack on another computer system. Floods the system with traffic, hence it crashes. 5. The proxy Trojans allows a hacker to turn user’s computer into HIS (Host Integration Server) server – to make purchases with stolen credit cards and run other organized criminal enterprises in particular user’s name.
  21. 21. 6. The FTP Trojan opens port 21 (the port for FTP transfer) and lets the attacker connect to your computer using File Transfer Protocol (FTP). 7. The security software disabler Trojan is designed to stop or kill security programs such as anti-virus software, firewalls, etc., without you knowing it.
  22. 22.  Transmitting medium : 1. spam or e-mail 2. a downloaded file 3. a disk from a trusted source 4. a legitimate program with the Trojan inside.  Trojan looks for your personal information and sends it to the Trojan writer (hacker). It can also allow the hacker to take full control of your system.
  23. 23.  For example, you download what appears to be a movie or music file, but when you click on it, you unleash a dangerous program that erases your disk, sends your credit card numbers and passwords to a stranger, or lets that stranger hack your computer to commit illegal Denial of service attacks .
  24. 24. 1. Clean Re-installation: Back up your entire hard disk, format the disk, re-install the operating system and all your applications from original CDs.
  25. 25. 2. Anti-Virus Software: Anti-virus software is always going to be playing catch up with active virus on the system. Make sure your computer has an anti virus program on it and update it regularly. If you have an auto- update option included in your anti-virus program you should turn it on; that way if you forget to update your software you can still be protected from threats Anti-Trojan Programs: These programs are the most effective against Trojan horse attacks, because they specialize in Trojans instead of general viruses.
  26. 26. NEVER download blindly from people or sites which you aren't 100% sure about Even if the file comes from a friend, you still must be sure what the file is before opening it NEVER use features in your programs that automatically get or preview files Never blindly type commands that others tell you to type, or go to web addresses mentioned by strangers, or run pre-fabricated programs or scripts
  27. 27. A simple example of a trojan horse would be a program named “waterfalls.scr" claiming to be a free waterfall screensaver which, when run, instead would allow access to the user's computer remotely. AIDS(trojanhorse) AIDS, also known as Aids Info Disk or PC Cyborg Trojan, is a trojan horse that replaces the AUTOEXEC.BAT file, which would then be used by AIDS to count the number times the computer has booted. Once this boot count reaches 90, AIDS hides directories and encrypts the names of all files on drive C: (rendering the system unusable).
  28. 28.  Spyware :  Spyware programs explore the files in an information system.  Information forwarded to an address specified in Spyware.  Spyware can also be used for investigation of software users or preparation of an attack.
  29. 29.  Trapdoor :  Secret undocumented entry point to the program.  An example of such feature is so called back door, which enables intrusion to the target by passing user authentication methods.  A hole in the security of a system deliberately left in place by designers or maintainers.  Trapdoor allows unauthorized access to the system.  Only purpose of a trap door is to "bypass" internal controls. It is up to the attacker to determine how this circumvention of control can be utilized for his benefit.
  30. 30. Types of Trapdoor Undetectable Trapdoor Virtually undetectable. Hardware Trapdoor Security-related hardware flaws.
  31. 31.  Worms :  program that spreads copies of itself through a network.  Does irrecoverable damage to the computer system.  Stand-alone program, spreads only through network.  Also performs various malicious activities other than spreading itself to different systems e.g., deleting files.
  32. 32. 1. Deleting files and other malicious actions on systems. 2. Communicate information back to attacker e.g., passwords, other proprietary information. 3. Disrupt normal operation of system, thus denial of service attack (DoS) – due to re- infecting infected system. 4. Worms may carry viruses with them.
  33. 33. Means of spreading Infection by Worms :  Infects one system, gain access to trusted host lists on infected system and spread to other hosts.  Another method of infection is penetrating a system by guessing passwords.  By exploiting widely known security holes, in case, password guessing and trusted host accessing fails. e.g., A well-known example of a worm is the ILOVEYOU worm, which invaded millions of computers through e-mail in 2000.
  34. 34.  Code Red ◦ July 2001 exploiting MS IIS bug ◦ probes random IP address, does DDoS attack  Code Red II variant includes backdoor  SQL Slammer ◦ early 2003, attacks MS SQL Server  Mydoom ◦ mass-mailing e-mail worm that appeared in 2004 ◦ installed remote access backdoor in infected systems  Warezov family of worms ◦ scan for e-mail addresses, send in attachment
  35. 35.  multiplatform  multi-exploit  ultrafast spreading  polymorphic  metamorphic  transport vehicles  zero-day exploit
  36. 36.  first appeared on mobile phones in 2004 target smartphone which can install s/w  they communicate via Bluetooth or MMS  to disable phone, delete data on phone, or send premium-priced messages  CommWarrior, launched in 2005 replicates using Bluetooth to nearby phones and via MMS using address-book numbers
  37. 37.  overlaps with anti-virus techniques  once worm on system A/V can detect  worms also cause significant net activity  worm defense approaches include: signature-based worm scan filtering filter-based worm containment payload-classification-based worm containment threshold random walk scan detection rate limiting and rate halting
  38. 38. Conclusion: Preventing infection by malicious software :  Use only trusted software, not pirated software.  Test all new software on isolated computer system.  Regularly take backup of the programs.  Use anti-virus software to detect and remove viruses.  Update virus database frequently to get new virus signatures.  Install firewall software, which hampers or prevents the functionality of worms and Trojan horses.  Make sure that the e-mail attachments are secure.  Do not keep a floppy disk in the drive when starting a program, unless sure that it does not include malicious software, else virus will be copied in the boot sector.
  39. 39.  Trojan Horse. Retrieved Nov 8, 2003 from website:  Staffordshire University, Information & Security Team (Jun 8, 2002). Information Systems Security Guidelines. Retrieved Nov 10, 2003 from website:  M.E.Kabay, Norwich University, VT (2002). Malicious Software. Retrieved Nov 9, 2003 from website:  Computer Emergency Response Team (CERT), Information Security (Jul 2, 2002). Malicious Software – general. Retrieved Nov 10, 2003 from website: