Protecting Windows networks from Malware

Madhur VermaMCSA, MCSE, MCTS, CIW Security Analyst,

CEH, MVP (Consumer Security)

Agenda

• Introduction and Background• Current Trends• Case Studies• Defense Arsenal• Best Practices

Immutable Laws of Security

Law#1: If a bad guy can persuade you to run his program on your computer, it's not your computer anymore

Law #2: If a bad guy can alter the operating system on your computer, it's not your computer anymore

Malware

"Malware" is short for malicious software and is typically used as a catch-all term to refer to any software designed to cause damage to a single computer, server, or computer network, whether it's a virus, spyware, et al.

Implications

• Theft of usernames & passwords• Theft of corporate secrets• Lost network bandwidth• Help desk overhead• Lost worker productivity• Legal Liabilities

Rationales

• Not using security devices • Mis-configuration of servers and network

devices• Installation of unwanted applications and

services• Poor coding practices• Using outdated Antivirus definitions

Malicious Software Landscape

Viruses, worms, Trojans, rootkits, bots

Adware, spyware, monitoring software, remote control software

Harmless

Potentially Unwanted

Malicious

Distribution Methods• Propagation through E-mail attachments, Pirated

software and free shareware programs• Mechanism: web pages can use to install

software is ActiveX• Mechanism of “Drive By download”• Deceptive technique of “Pop under exploit”

– choice of clicking Yes/Ok or No/cancel• Faux Security Alert

Changing Era• Increased propagation vectors• Complexity of malicious code, payload and

obfuscation• Motivation changed from fun, curiosity or fame to

money• Destruction malware decreasing and information

stealing malware increasing• Rise in targeted attacks through social engineering• Rise in Malware Toolkits• Rise in exploitation of Web 2.0

Current Trends

• Compromising trusted and popular websites and embedding malicious code or links to malicious sites

• Publishing malicious links in search engines, discussion forums etc

• Development of web-attack toolkits• Exploiting client side vulnerabilities

Case Study I - Facebook

Facebook Widget Installing Spyware

Case Study II - Google

Google Sponsored Links Spreading Rogue Anti-Virus Software

Case Study III - Toolkits

Attack Toolkit

iFrame Snippet

Intrude & adds IFRAME Snippet

Malicious Code injected into users’ PC

Threat Ecosystem

Facts

Source: Microsoft Intelligence Report

Facts

• Rise in web application vulnerabilities• Rise in exploitation of client-side vulnerabilities• Rise in browser based and browser plug-in based vulnerabilities

Source: Symantec

Defensive Arsenal

Policies, Procedures, and Awareness

• Using a layered approach– Increases attacker’s risk of detection – Reduces attacker’s chance of success

OS hardening, authentication, patch management, HIPS

Firewalls, VPN quarantine

Guards, locks, tracking devices

Network segments, IPSec, NIPS

Application hardening, antivirus, antispywareACL, encryption

Security Policy, User education

Physical Security

Perimeter

Internal Network

Host

Application

Data

Defense-in-Depth

Implementing Application Layer Filtering

• Web browsing and e-mail can be scanned to ensure that content specific to each does not contain illegitimate data

• Deep content analyses, including the ability to detect, inspect and validate traffic using any port and protocol

Protecting the Network: Best Practices

• Have a proactive antivirus response team monitoring early warning sites such as antivirus vendor Web sites

• Have an incident response plan• Implement automated monitoring and report

policies• Implement intrusion- detection or intrusion-

prevention capabilities

Protecting Servers: Best Practices

• Consider each server role implemented in your organization to implement specific host protection solutions

• Stage all updates through a test environment before releasing into production

• Deploy regular security and antivirus updates as required

• Implement a self-managed host protection solution to decrease management costs

Protecting Client Computers: Best Practices

• Identify threats within the host, application, and data layers of the defense-in-depth strategy

• Implement an effective security update management policy

• Implement an effective antivirus management policy

• Use Active Directory Group Policy to manage application security requirements

• Implement software restriction policies to control applications

Guidance

Developer Tools

SystemsManagementActive Directory

Federation Services (ADFS)

Identity

Management

Content

Services

Client and Server OS

Server Applicatio

ns

Edge

Network Access Protection (NAP)

A Comprehensive Security Solution

Best Practices

• Always run up-to-date software

• Uninstall unnecessary services and applications

• Use antivirus and antispyware that offers real-time protection and continually updated definition files to detect and block exploits

• Enable Data Execution Prevention (DEP) in compatible versions of Windows, which can help prevent a common class of exploits called buffer overflows

Best Practices

• Enable Structured Exception Handling Overwrite Protection (SEHOP) in Windows Vista SP1 and Windows Server 2008, which is designed to block exploits that use the Structured Exception Handler (SEH) overwrite technique

• Set Internet and local intranet security zone settings in Internet Explorer to High, which will cause Internet Explorer to prompt the user before running scripts and ActiveX controls in these zones

Best Practices

• Avoid browsing to sites you do not trust

• Follow principle of least privilege

• Read e-mail messages in plain text format to help protect you from the HTML e-mail attack vector

• Do not click on the links provided in the e-mail from the sources you do not trust

Immutable Laws of Security

• If you don't keep up with security fixes, your network won't be yours for long

• It doesn't do much good to install security fixes on a computer that was never secured to begin with

• Security only works if the secure way also happens to be the easy way

• Eternal vigilance is the price of security

Questions?