What about viruses and other malware?
Java Security,Windows code security, Windows Server 2003 Security,Internet Explorer 7 Security and Internet Firewalls questions and answers
(Continued from previous question...)
What about viruses and other malware?
Firewalls can't protect very well against things like viruses or malicious software (malware). There are too many ways of encoding binary files for transfer over networks, and too many different architectures and viruses to try to search for them all. In other words, a firewall cannot replace security-consciousness on the part of your users. In general, a firewall cannot protect against a data-driven attack--attacks in which something is mailed or copied to an internal host where it is then executed. This form of attack has occurred in the past against various versions of sendmail, ghostscript, scripting mail user agents like Outlook, and Web browsers like Internet Explorer.
Organizations that are deeply concerned about viruses should implement organization-wide virus control measures. Rather than only trying to screen viruses out at the firewall, make sure that every vulnerable desktop has virus scanning software that is run when the machine is rebooted. Blanketing your network with virus scanning software will protect against viruses that come in via floppy disks, CDs, modems, and the Internet. Trying to block viruses at the firewall will only protect against viruses from the Internet. Virus scanning at the firewall or e-mail gateway will stop a large number of infections.
Nevertheless, an increasing number of firewall vendors are offering ``virus detecting'' firewalls. They're probably only useful for naive users exchanging Windows-on-Intel executable programs and malicious-macro-capable application documents. There are many firewall-based approaches for dealing with problems like the ``ILOVEYOU'' worm and related attacks, but these are really oversimplified approaches that try to limit the damage of something that is so stupid it never should have occurred in the first place. Do not count on any protection from attackers with this feature. (Since ``ILOVEYOU'' went around, we've seen at least a half-dozen similar attacks, including Melissa, Happy99, Code Red, and Badtrans.B, all of which were happily passed through many virus-detecting firewalls and e-mail gateways.)
A strong firewall is never a substitute for sensible software that recognizes the nature of what it's handling--untrusted data from an unauthenticated party--and behaves appropriately. Do not think that because ``everyone'' is using that mailer or because the vendor is a gargantuan multinational company, you're safe. In fact, it isn't true that ``everyone'' is using any mailer, and companies that specialize in turning technology invented elsewhere into something that's ``easy to use'' without any expertise are more likely to produce software that can be fooled. Further consideration of this topic would be worthwhile [3], but is beyond the scope of this document.
(Continued on next question...)
Other Interview Questions
- Is Java secure?
- What are the risks?
- How common are security breaches?
- Who is at risk?
- How can I protect myself?
- What about products that claim to detect malicious applets?
- What about products that claim to block Java applets at a firewall?
- Which is more secure: Java or ActiveX?
- Which version of my browser should I use?
- What about ``hostile applets?''
- I run a Web server. Am I at risk?
- What about JavaScript?
- What’s the difference between code-based security and role-based security? Which one is better?
- How can you work with permissions from your .NET application?
- How can C# app request minimum permissions?
- What’s a code group?
- What’s the difference between authentication and authorization?
- What are the authentication modes in ASP.NET?
- Are the actual permissions for the application defined at run-time or compile-time?
- # What’s the difference between local, global and universal groups?
- # I am trying to create a new universal user group. Why can’t I?
- # What is LSDOU?
- # Why doesn’t LSDOU work under Windows NT?
- # Where are group policies stored?
- # What is GPT and GPC?
- # Where is GPT stored?
- # You change the group policies, and now the computer and user settings are in conflict. Which one has the highest priority?
- # You want to set up remote installation procedure, but do not want the user to gain access over it. What do you do? gponame–>
- # What’s contained in administrative template conf.adm?
- # How can you restrict running certain applications on a machine?
- # You need to automatically install an app, but MSI file is not available. What do you do?
- # What’s the difference between Software Installer and Windows Installer?
- # What can be restricted on Windows Server 2003 that wasn’t there in previous products?
- # How frequently is the client policy refreshed?
- # Where is secedit?
- # You want to create a new group policy but do not wish to inherit.
- # What is "tattooing" the Registry?
- # How do you fight tattooing in NT/2000 installations?
- # How do you fight tattooing in 2003 installations?
- # What does IntelliMirror do?
- # What’s the major difference between FAT and NTFS on a local machine?
- # How do FAT and NTFS differ in approach to user shares?
- # Explan the List Folder Contents permission on the folder in NTFS.
- # I have a file to which the user has access, but he has no folder permission to read it. Can he access it?
- # For a user in several groups, are Allow permissions restrictive or permissive?
- # For a user in several groups, are Deny permissions restrictive or permissive?
- # What hidden shares exist on Windows Server 2003 installation?
- # What’s the difference between standalone and fault-tolerant DFS (Distributed File System) installations?
- # We’re using the DFS fault-tolerant installation, but cannot access it from a Win98 box.
- # Where exactly do fault-tolerant DFS shares store information in Active Directory?
- # Can you use Start->Search with DFS shares?
- # What problems can you have with DFS installed?
- # I run Microsoft Cluster Server and cannot install fault-tolerant DFS.
- # Is Kerberos encryption symmetric or asymmetric?
- # How does Windows 2003 Server try to prevent a middle-man attack on encrypted line?
- # What hashing algorithms are used in Windows 2003 Server?
- # What third-party certificate exchange protocols are used by Windows 2003 Server?
- # What’s the number of permitted unsuccessful logons on Administrator account?
- # If hashing is one-way function and Windows Server uses hashing for storing passwords, how is it possible to attack the password lists, specifically the ones using NTLMv1?
- # What’s the difference between guest accounts in Server 2003 and other editions?
- # How many passwords by default are remembered when you check "Enforce Password History Remembered"?
- #1: Default protection from potentially dangerous Active X controls
- #2: Per-zone control of Active X opt-in
- #3: Site and zone locking for Active X controls
- #4: Protection against phishing
- #5: Cross-domain security
- #6: Locked down security zones
- #7: Better SSL/TLS notification and digital certificate info
- #8: Privacy protection features
- #9: Address bars
- #10: International character alert
- What is a network firewall?
- Why would I want a firewall?
- What can a firewall protect against?
- What can't a firewall protect against?
- What about viruses and other malware?
- Will IPSEC make firewalls obsolete?
- Where can I get more information on firewalls on the Internet?
- What are some of the basic design decisions in a firewall?
- What are the basic types of firewalls?
- Network layer firewalls
- Application layer firewalls
- What are proxy servers and how do they work?
- What are some cheap packet screening tools?
- What are some reasonable filtering rules for a kernel-based packet screen?
- What are some reasonable filtering rules for a Cisco?
- What are the critical resources in a firewall?
- What is a DMZ, and why do I want one?
- How might I increase the security and scalability of my DMZ?
- What is a `single point of failure', and how do I avoid having one?
- How can I block all of the bad stuff?
- How can I restrict web access so users can't view sites unrelated to work?
- What is source routed traffic and why is it a threat?
- What are ICMP redirects and redirect bombs?
- What about denial of service?
- What are some common attacks, and how can I protect my system against them?
- Do I really want to allow everything that my users ask for?
- How do I make Web/HTTP work through my firewall?
- How do I make SSL work through the firewall?
- How do I make DNS work with a firewall?
- How do I make FTP work through my firewall?
- How do I make Telnet work through my firewall?
- How do I make Finger and whois work through my firewall?
- How do I make gopher, archie, and other services work through my firewall?
- What are the issues about X11 through a firewall?
- How do I make RealAudio work through my firewall?
- How do I make my web server act as a front-end for a database that lives on my private network?
- But my database has an integrated web server, and I want to use that. Can't I just poke a hole in the firewall and tunnel that port?
- How Do I Make IP Multicast Work With My Firewall?
- What is a port?
- How do I know which application uses what port?
- What are LISTENING ports?
- How do I determine what service the port is for?
- What ports are safe to pass through a firewall?
- The behavior of FTP
- What software uses what FTP mode?
- Is my firewall trying to connect outside?
- The anatomy of a TCP connection
- Glossary of Firewall-Related Terms
|