Identity theft and computer security

identity-theftIdentity theft and computer security

Identity theft

Would you like to find out what those-in-the-know have to say about computer security? The information in the article below comes straight from well-informed experts with special knowledge about computer security.
Once you begin to move beyond basic background information, you begin to realize that there's more to computer security than you may have first thought.
What is computer security?
Computer security is the process of preventing and detecting unauthorized use of your computer. Prevention measures help you to stop unauthorized users (also known as "intruders") from accessing any part of your computer system. Detection helps you to determine whether or not someone attempted to break into your system, if they were successful, and what they may have done.
Why should I care about computer security?
We use computers for everything from banking and investing to shopping and communicating with others through email or chat programs. Although you may not consider your communications "top secret," you probably do not want strangers reading your email, using your computer to attack other systems, sending forged email from your computer, or examining personal information stored on your computer (such as financial statements).
Who would want to break into my computer at home?
Intruders (also referred to as hackers, attackers, or crackers) may not care about your identity. Often they want to gain control of your computer so they can use it to launch attacks on other computer systems.
Having control of your computer gives them the ability to hide their true location as they launch attacks, often against high-profile computer systems such as government or financial systems. Even if you have a computer connected to the Internet only to play the latest games or to send email to friends and family, your computer may be a target.
Intruders may be able to watch all your actions on the computer, or cause damage to your computer by reformatting your hard drive or changing your data.
How easy is it to break into my computer?
Unfortunately, intruders are always discovering new vulnerabilities (informally called "holes") to exploit in computer software. The complexity of software makes it increasingly difficult to thoroughly test the security of computer systems.
When holes are discovered, computer vendors will usually develop patches to address the problem(s). However, it is up to you, the user, to obtain and install the patches, or correctly configure the software to operate more securely. Most of the incident reports of computer break-ins received at the CERT/CC could have been prevented if system administrators and users kept their computers up-to-date with patches and security fixes.
Also, some software applications have default settings that allow other users to access your computer unless you change the settings to be more secure. Examples include chat programs that let outsiders execute commands on your computer or web browsers that could allow someone to place harmful programs on your computer that run when you click on them.
What is at risk?
Information security is concerned with three main areas:
Confidentiality - information should be available only to those who rightfully have access to it
Integrity -- information should be modified only by those who are authorized to do so
Availability -- information should be accessible to those who need it when they need it
These concepts apply to home Internet users just as much as they would to any corporate or government network. You probably wouldn't let a stranger look through your important documents. In the same way, you may want to keep the tasks you perform on your computer confidential, whether it's tracking your investments or sending email messages to family and friends. Also, you should have some assurance that the information you enter into your computer remains intact and is available when you need it.
Some security risks arise from the possibility of intentional misuse of your computer by intruders via the Internet. Others are risks that you would face even if you weren't connected to the Internet (e.g. hard disk failures, theft, power outages). The bad news is that you probably cannot plan for every possible risk. The good news is that you can take some simple steps to reduce the chance that you'll be affected by the most common threats -- and some of those steps help with both the intentional and accidental risks you're likely to face.
Before we get to what you can do to protect your computer or home network, let’s take a closer look at some of these risks.
Intentional misuse of your computer
The most common methods used by intruders to gain control of home computers are briefly described below. More detailed information is available by reviewing the URLs listed in the References section below.
Trojan horse programs
Back door and remote administration programs
Denial of service
Being an intermediary for another attack
Unprotected Windows shares
Mobile code (Java, JavaScript, and ActiveX)
Cross-site scripting
Email spoofing
Email-borne viruses
Hidden file extensions
Chat clients
Packet sniffing
Trojan horse programs
Trojan horse programs are a common way for intruders to trick you (sometimes referred to as "social engineering") into installing "back door" programs. These can allow intruders easy access to your computer without your knowledge, change your system configurations, or infect your computer with a computer virus. More information about Trojan horses can be found in the following document.
http://www.cert.org/advisories/CA-1999-02.html
Back door and remote administration programs
On Windows computers, three tools commonly used by intruders to gain remote access to your computer are BackOrifice, Netbus, and SubSeven. These back door or remote administration programs, once installed, allow other people to access and control your computer.
Denial of service
Another form of attack is called a denial-of-service (DoS) attack. This type of attack causes your computer to crash or to become so busy processing data that you are unable to use it. In most cases, the latest patches will prevent the attack. The following documents describe denial-of-service attacks in greater detail.
http://www.cert.org/advisories/CA-2000-01.html
http://www.cert.org/archive/pdf/DoS_trends.pdf
It is important to note that in addition to being the target of a DoS attack, it is possible for your computer to be used as a participant in a denial-of-service attack on another system.
Being an intermediary for another attack
Intruders will frequently use compromised computers as launching pads for attacking other systems. An example of this is how distributed denial-of-service (DDoS) tools are used. The intruders install an "agent" (frequently through a Trojan horse program) that runs on the compromised computer awaiting further instructions. Then, when a number of agents are running on different computers, a single "handler" can instruct all of them to launch a denial-of-service attack on another system. Thus, the end target of the attack is not your own computer, but someone else’s -- your computer is just a convenient tool in a larger attack.
Unprotected Windows shares
Unprotected Windows networking shares can be exploited by intruders in an automated way to place tools on large numbers of Windows-based computers attached to the Internet. Because site security on the Internet is interdependent, a compromised computer not only creates problems for the computer's owner, but it is also a threat to other sites on the Internet. The greater immediate risk to the Internet community is the potentially large number of computers attached to the Internet with unprotected Windows networking shares combined with distributed attack tools such as those described in
http://www.cert.org/incident_notes/IN-2000-01.html
Another threat includes malicious and destructive code, such as viruses or worms, which leverage unprotected Windows networking shares to propagate. One such example is the 911 worm described in
http://www.cert.org/incident_notes/IN-2000-03.html
There is great potential for the emergence of other intruder tools that leverage unprotected Windows networking shares on a widespread basis.
Mobile code (Java/JavaScript/ActiveX)
There have been reports of problems with "mobile code" (e.g. Java, JavaScript, and ActiveX). These are programming languages that let web developers write code that is executed by your web browser. Although the code is generally useful, it can be used by intruders to gather information (such as which web sites you visit) or to run malicious code on your computer. It is possible to disable Java, JavaScript, and ActiveX in your web browser. We recommend that you do so if you are browsing web sites that you are not familiar with or do not trust.
Also be aware of the risks involved in the use of mobile code within email programs. Many email programs use the same code as web browsers to display HTML. Thus, vulnerabilities that affect Java, JavaScript, and ActiveX are often applicable to email as well as web pages.
More information on ActiveX security is available in http://www.cert.org/archive/pdf/activeX_report.pdf
Cross-site scripting
A malicious web developer may attach a script to something sent to a web site, such as a URL, an element in a form, or a database inquiry. Later, when the web site responds to you, the malicious script is transferred to your browser. You can potentially expose your web browser to malicious scripts by following links in web pages, email messages, or newsgroup postings without knowing what they link to
using interactive forms on an untrustworthy site viewing online discussion groups, forums, or other dynamically generated pages where users can post text containing HTML tags
More information regarding the risks posed by malicious code in web links can be found in CA-2000-02 Malicious HTML Tags Embedded in Client Web Requests.
Email spoofing
Email “spoofing” is when an email message appears to have originated from one source when it actually was sent from another source. Email spoofing is often an attempt to trick the user into making a damaging statement or releasing sensitive information (such as passwords).
Spoofed email can range from harmless pranks to social engineering ploys. Examples of the latter include:
email claiming to be from a system administrator requesting users to change their passwords to a specified string and threatening to suspend their account if they do not comply
email claiming to be from a person in authority requesting users to send them a copy of a password file or other sensitive information
Note that while service providers may occasionally request that you change your password, they usually will not specify what you should change it to. Also, most legitimate service providers would never ask you to send them any password information via email. If you suspect that you may have received a spoofed email from someone with malicious intent, you should contact your service provider's support personnel immediately.
Email borne viruses
Viruses and other types of malicious code are often spread as attachments to email messages. Before opening any attachments, be sure you know the source of the attachment. It is not enough that the mail originated from an address you recognize. The Melissa virus (see References) spread precisely because it originated from a familiar address. Also, malicious code might be distributed in amusing or enticing programs.
Many recent viruses use these social engineering techniques to spread. Examples include
W32/Sircam -- http://www.cert.org/advisories/CA-2001-22.html
W32/Goner -- http://www.cert.org/incident_notes/IN-2001-15.html
Never run a program unless you know it to be authored by a person or company that you trust. Also, don't send programs of unknown origin to your friends or coworkers simply because they are amusing -- they might contain a Trojan horse program.
Hidden file extensions
Windows operating systems contain an option to "Hide file extensions for known file types". The option is enabled by default, but a user may choose to disable this option in order to have file extensions displayed by Windows. Multiple email-borne viruses are known to exploit hidden file extensions. The first major attack that took advantage of a hidden file extension was the VBS/LoveLetter worm which contained an email attachment named "LOVE-LETTER-FOR-YOU.TXT.vbs". Other malicious programs have since incorporated similar naming schemes. Examples include
Downloader (MySis.avi.exe or QuickFlick.mpg.exe)
VBS/Timofonica (TIMOFONICA.TXT.vbs)
VBS/CoolNote (COOL_NOTEPAD_DEMO.TXT.vbs)
VBS/OnTheFly (AnnaKournikova.jpg.vbs)
The files attached to the email messages sent by these viruses may appear to be harmless text (.txt), MPEG (.mpg), AVI (.avi) or other file types when in fact the file is a malicious script or executable (.vbs or .exe, for example).
Chat clients
Internet chat applications, such as instant messaging applications and Internet Relay Chat (IRC) networks, provide a mechanism for information to be transmitted bi-directionally between computers on the Internet. Chat clients provide groups of individuals with the means to exchange dialog, web URLs, and in many cases, files of any type.
Because many chat clients allow for the exchange of executable code, they present risks similar to those of email clients. As with email clients, care should be taken to limit the chat client’s ability to execute downloaded files. As always, you should be wary of exchanging files with unknown parties.
computadoraPacket sniffing
A packet sniffer is a program that captures data from information packets as they travel over the network. That data may include user names, passwords, and proprietary information that travels over the network in clear text. With perhaps hundreds or thousands of passwords captured by the packet sniffer, intruders can launch widespread attacks on systems. Installing a packet sniffer does not necessarily require administrator-level access.
Relative to DSL and traditional dial-up users, cable modem users have a higher risk of exposure to packet sniffers since entire neighborhoods of cable modem users are effectively part of the same LAN. A packet sniffer installed on any cable modem user's computer in a neighborhood may be able to capture data transmitted by any other cable modem in the same neighborhood.
Accidents and other risks
In addition to the risks associated with connecting your computer to the Internet, there are a number of risks that apply even if the computer has no network connections at all. Most of these risks are well-known, so we won’t go into much detail in this document, but it is important to note that the common practices associated with reducing these risks may also help reduce susceptibility to the network-based risks discussed above.
Disk failure
Recall that availability is one of the three key elements of information security. Although all stored data can become unavailable -- if the media it’s stored on is physically damaged, destroyed, or lost -- data stored on hard disks is at higher risk due to the mechanical nature of the device. Hard disk crashes are a common cause of data loss on personal computers. Regular system backups are the only effective remedy.
Power failure and surges
Power problems (surges, blackouts, and brown-outs) can cause physical damage to a computer, inducing a hard disk crash or otherwise harming the electronic components of the computer. Common mitigation methods include using surge suppressors and uninterruptible power supplies (UPS).
Physical Theft
Physical theft of a computer, of course, results in the loss of confidentiality and availability, and (assuming the computer is ever recovered) makes the integrity of the data stored on the disk suspect. Regular system backups (with the backups stored somewhere away from the computer) allow for recovery of the data, but backups alone cannot address confidentiality. Cryptographic tools are available that can encrypt data stored on a computer’s hard disk. The CERT/CC encourages the use of these tools if the computer contains sensitive data or is at high risk of theft (e.g. laptops or other portable computers).
Actions home users can take to protect their computer systems
The CERT/CC recommends the following practices to home users:
Consult your system support personnel if you work from home
Use virus protection software
Use a firewall
Don’t open unknown email attachments
Don’t run programs of unknown origin
Disable hidden filename extensions
Keep all applications (including your operating system) patched
Turn off your computer or disconnect from the network when not in use
Disable Java, JavaScript, and ActiveX if possible
Disable scripting features in email programs
Make regular backups of critical data
Make a boot disk in case your computer is damaged or compromised
Further discussion on each of these points is given below.
Recommendations
Consult your system support personnel if you work from home
If you use your broadband access to connect to your employer's network via a Virtual Private Network (VPN) or other means, your employer may have policies or procedures relating to the security of your home network. Be sure to consult with your employer's support personnel, as appropriate, before following any of the steps outlined in this document.
Use virus protection software
The CERT/CC recommends the use of anti-virus software on all Internet-connected computers. Be sure to keep your anti-virus software up-to-date. Many anti-virus packages support automatic updates of virus definitions. We recommend the use of these automatic updates when available.
Use a firewall
We strongly recommend the use of some type of firewall product, such as a network appliance or a personal firewall software package. Intruders are constantly scanning home user systems for known vulnerabilities. Network firewalls (whether software or hardware-based) can provide some degree of protection against these attacks. However, no firewall can detect or stop all attacks, so it’s not sufficient to install a firewall and then ignore all other security measures.
Don't open unknown email attachments
Before opening any email attachments, be sure you know the source of the attachment. It is not enough that the mail originated from an address you recognize. The Melissa virus spread precisely because it originated from a familiar address. Malicious code might be distributed in amusing or enticing programs.
If you must open an attachment before you can verify the source, we suggest the following procedure:
be sure your virus definitions are up-to-date (see "Use virus protection software" above)
save the file to your hard disk
scan the file using your antivirus software
open the file
For additional protection, you can disconnect your computer's network connection before opening the file.
Following these steps will reduce, but not wholly eliminate, the chance that any malicious code contained in the attachment might spread from your computer to others.
Don't run programs of unknown origin
Never run a program unless you know it to be authored by a person or company that you trust. Also, don't send programs of unknown origin to your friends or coworkers simply because they are amusing -- they might contain a Trojan horse program.
Disable hidden filename extensions
Windows operating systems contain an option to "Hide file extensions for known file types". The option is enabled by default, but you can disable this option in order to have file extensions displayed by Windows. After disabling this option, there are still some file extensions that, by default, will continue to remain hidden.
There is a registry value which, if set, will cause Windows to hide certain file extensions regardless of user configuration choices elsewhere in the operating system. The "NeverShowExt" registry value is used to hide the extensions for basic Windows file types. For example, the ".LNK" extension associated with Windows shortcuts remains hidden even after a user has turned off the option to hide extensions.
Specific instructions for disabling hidden file name extensions are given in http://www.cert.org/incident_notes/IN-2000-07.html
Keep all applications, including your operating system, patched
Vendors will usually release patches for their software when a vulnerability has been discovered. Most product documentation offers a method to get updates and patches. You should be able to obtain updates from the vendor's web site. Read the manuals or browse the vendor's web site for more information.
Some applications will automatically check for available updates, and many vendors offer automatic notification of updates via a mailing list. Look on your vendor's web site for information about automatic notification. If no mailing list or other automated notification mechanism is offered you may need to check periodically for updates.
Turn off your computer or disconnect from the network when not in use
Turn off your computer or disconnect its Ethernet interface when you are not using it. An intruder cannot attack your computer if it is powered off or otherwise completely disconnected from the network.
Disable Java, JavaScript, and ActiveX if possible
Be aware of the risks involved in the use of "mobile code" such as ActiveX, Java, and JavaScript. A malicious web developer may attach a script to something sent to a web site, such as a URL, an element in a form, or a database inquiry. Later, when the web site responds to you, the malicious script is transferred to your browser.
The most significant impact of this vulnerability can be avoided by disabling all scripting languages. Turning off these options will keep you from being vulnerable to malicious scripts. However, it will limit the interaction you can have with some web sites.
Many legitimate sites use scripts running within the browser to add useful features. Disabling scripting may degrade the functionality of these sites.
More information on ActiveX security, including recommendations for users who administer their own computers, is available in http://www.cert.org/archive/pdf/activeX_report.pdf
More information regarding the risks posed by malicious code in web links can be found in CA-2000-02 Malicious HTML Tags Embedded in Client Web Requests.
Disable scripting features in email programs
Because many email programs use the same code as web browsers to display HTML, vulnerabilities that affect ActiveX, Java, and JavaScript are often applicable to email as well as web pages. Therefore, in addition to disabling scripting features in web browsers (see "Disable Java, JavaScript, and ActiveX if possible", above), we recommend that users also disable these features in their email programs.
Make regular backups of critical data
Keep a copy of important files on removable media such as ZIP disks or recordable CD-ROM disks (CD-R or CD-RW disks). Use software backup tools if available, and store the backup disks somewhere away from the computer.
Make a boot disk in case your computer is damaged or compromised
To aid in recovering from a security breach or hard disk failure, create a boot disk on a floppy disk which will help when recovering a computer after such an event has occurred. Remember, however, you must create this disk before you have a security event.
5 important tips:
when you get anything with your name, address, Social Security Number, or any account numbers don't just throw it away in the trash. This makes it easy for people to steal your information and your identity. Shred these papers through a paper shredder. If you don't have a paper shredder then use scissors and shred them that way. It may be tough shredding with sissors, but it will be even tougher fighting to gain back your identity.
keep it to yourself! Don't post your phone number, address, and other personal information on social networks. Keep this especially away from Myspace, Facebook, Ect. I would not recommend it, but if you need to share your information with another person on a social site then message that person in private.
make your checks go to the bank. That's right, when you reorder bank checks have them sent to the bank. It is safer than having them sent to your home mailbox. Another tip is to know it is safer to reorder your checks from your bank instead of an outside vendor or third party. When your checks are just head to the bank to pick them up.
eye the calendar. Get yourself a calendar so you can keep track of when bills from places, like the credit cards company, should be coming in. When they have not been received in your mailbox as normal you should call right away and ask when they were mailed out. Also make the person check your address so you know no one changed the mailing address in an attempt to steal your identity.
I hope that reading the above information was both enjoyable and educational for you. Your learning process should be ongoing--the more you understand about any subject, the more you will be able to share with others.
keep it to yourself. Do not order anything over the phone and then call out your credit card or debit card numbers. This is easy for a theft to get your information. Also when using the PIN pad either hover over the key pad or turn it upside down so the people behind you can't see what your hitting. Don't be shy about hiding it because this is your identity.

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