Recent Internet Viruses & Worms

ByDoppalapudi Raghu

Outline

• History of Malicious Logic• Types of Viruses & Worms• Recent Internet viruses • Recent Internet Worms• Defense • Good Habits in Computer world

History

• Definition of malicious logic• Fred cohen• Brain Virus(1986)• MacMag peace virus(1987)• Duff’s Experiment virus(1987)

Difference between Internet virus and Internet worm

Virus Worm

Need a host file No need of host fileIt’s a variant of virus

Human intervention No human Intervention

It infects the files and infect other systems by sharing these files

Infects computers and spread over network

Causes damage to hardware, software

Consumes too much system resources or N/W bandwidth.

Understanding Virus namesSymantec Notation

• Family name• Names for the variants in a virus family• Suffix is added to the names in the same virus

family• Examples• badvirus.a----------badvirus.z• badvirus.aa--------badvirus.az• badvirus.ba--------badvirus.bz

Terminology in virus world

• ZERO DAY EXPLOIT• Proof of concept• Zombie computer• Ethical Hacker• Payload• Honey pots

Types of viruses• Boot sector Infectors• Executable Infectors• Multipartite Viruses• TSR Viruses• Stealth Viruses• Encrypted Viruses• Polymorphic Viruses• Macro Viruses• Many new virus types are added to the list

• Companion virus file with same name is created but with extension higher in

execution hierarchy• Link virus

These viruses create changes to the File allocation table

Types of Wormsworms

Email worms

IRC worms

File sharing network worms

Internet worms

Instant Messaging worms

Virus.win32.VB.cx

• Jan 12th 2007• Virus scans victims machine for executable files.• Virus itself is a windows PE .exe files• Contents of the files with

extension .cpp, .doc, .htm, .html, .txt, .xls will be overwritten with following text

• "Sorry!!!! $%%#@&re*$%$rthn#$^&&!f#&%$$f$#df#@^%$~`<:JHFgYttrt" "$%%%7``0924ksh<:{[86#$36455hgf#$45"

W32/FUJACKS.AB • 4/7/2007• Infects .exe files also infects web pages by

Inserting malicious hyperlinks of windows ani exploit

• It creates the following registry key to start itself at boot up time: HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run\Death.exe\"\%system%\Death.

• Terminates the processes containing the strings like zone alarm, Symantec anti virus.

• It also attempts to download other malware

Effects of Win32.fujacks• Infected through network shares which are protected with very

weak passwords.• This virus tries with passwords present in the directory.• Change in the executable file sizes.• Creates the following files in root directory: setup.inf, setup.exe, GameSetup.exe

Windows Vulnerabilities• W1 Web Servers & Services • W2 Workstation Service • W3 Windows Remote Access Services • W4 Microsoft SQL Server (MSSQL) • W5 Windows Authentication • W6 Web Browsers • W7 File-Sharing Applications • W8 LSAS Exposures • W9 Mail Client • W10 Instant Messaging • W11 ani vulnerability

Windows .ANI vulnerability

• Determina security • User32.DLL code has vulnerability• Buffer overflow• Remote code execution• Microsoft released patches on April 5th

Code Red Worm• July 13 2001• Worm spread using .ida (indexing

service) vulnerability in Microsoft Internet Information Server

• Damage caused:• Infected machines randomly

attacked other web servers• Performed denial of service attack

on www.whitehouse.gov• The homepage of infected

machines is defaced

Code red worm working

Spida Worm• Microsoft SQL server vulnerability• Different worm exploiting databases• On SQL server 7.0 password is blank by default• Connect to sa with blank password• The worm uses the extended stored procedure

xp_cmdshell

My tob worm

• Mass mailing worm• It can use even the LSASS vulnerability of windows• Stack based buffer overflow• It sends itself to all email addresses harvested from the victim

machine using its own email engine• Aug 9 2005 the proof of concept was released & by aug 11th

worms started attacking.• My tob worm was designed from some version of my doom

Worms at a glance

• Vulnerability• Spreading methods• Infecting

Fighting Internet worms• Honey pots• Computer elements to delude aggressors• 2 kinds of honey pots are used• High Interaction• Low Interaction• Honey pots versus worms• Honey pots and worm infections• Honey pots and payload worms• Honey pots and propagation of worms

How anti-virus software works• Virus dictionary approach• DAT files are released by the Anti virus company.• These DAT files have virus definitions and signatures of the

virus.• Suspicious behavior approach• Other ways to detect viruses• Sandboxing

Good practices • Install the patches supplied by the software vendors• Keep your Antivirus software updated• Do not open the email attachments from the unknown.• Configure the firewall properly• Use strong passwords so that others cant brute force • Be aware of the Internet viruses and worms • Zero day exploits cannot be avoided.

Kaspersky discovers an iVirus • Even the I pods are effected with viruses• Last year 2 viruses were found which infected during

manufacturing process• Podloso virus is the proof of concept• Currently it does not have any malicious payload• It just display a message on the screen that

“You are infected with Oslo the first iPodLinux Virus.”