Knowledge Base

Steps that you can take to help identify and to help protect yourself from deceptive (spoofed) Web sites and malicious hyperlinks

Article ID: 833786

Article Last Modified on 9/27/2007

APPLIES TO

Microsoft Internet Explorer 6.0, when used with:
- Microsoft Windows Server 2003, Datacenter Edition (32-bit x86)
- the operating system: Microsoft Windows Server 2003, Enterprise Edition
- Microsoft Windows Server 2003, Standard Edition (32-bit x86)
- Microsoft Windows Server 2003, Web Edition
- Microsoft Windows XP Professional
- the operating system: Microsoft Windows Server 2003, 64-Bit Datacenter Edition
- the operating system: Microsoft Windows Server 2003, 64-Bit Enterprise Edition
- Microsoft Windows XP Professional for Itanium-based systems
Microsoft Internet Explorer 6.0 Service Pack 1, when used with:
- Microsoft Windows XP Professional
- Microsoft Windows XP Embedded
- Microsoft Windows 2000 Service Pack 2
- Microsoft Windows 2000 Service Pack 3
- Microsoft Windows 2000 Service Pack 4
- Microsoft Windows NT 4.0 Service Pack 6a
- Microsoft Windows Millennium Edition
- Microsoft Windows 98 Second Edition
Microsoft Internet Explorer 6.0, when used with:
- Microsoft Windows XP Professional for Itanium-based systems
Microsoft Internet Explorer 5.5, when used with:
- Microsoft Windows 2000 Service Pack 2
- Microsoft Windows 2000 Service Pack 3
- Microsoft Windows 2000 Service Pack 4
- Microsoft Windows NT 4.0 Service Pack 6a
- Microsoft Windows Millennium Edition
- Microsoft Windows 98 Second Edition
Microsoft Internet Explorer 5.01 Service Pack 4, when used with:
- Microsoft Windows 2000 Service Pack 4
Microsoft Internet Explorer 5.01 Service Pack 3, when used with:
- Microsoft Windows 2000 Service Pack 3
Microsoft Internet Explorer 5.01 Service Pack 2, when used with:
- Microsoft Windows 2000 Service Pack 2

SUMMARY

When you point to a hyperlink in Microsoft Internet Explorer, Microsoft Outlook Express, or Microsoft Outlook, the address of the Web site typically appears in the Status bar at the bottom of the window. After you click a link that opens in Internet Explorer, the address of the Web site typically appears in the Internet Explorer Address bar, and the title of the Web page typically appears in the Title bar of the window.

However, a malicious user could create a link to a deceptive (spoofed) Web site that displays the address, or URL, to a legitimate Web site in the Status bar, Address bar, and Title bar. This article describes steps that you can take to help mitigate this issue and to help you to identify a deceptive (spoofed) Web site or URL.

MORE INFORMATION

This article discusses steps you can take to help protect yourself from spoofed Web sites. To summarize, these steps are:

Install the MS04-004 Cumulative Security Update for Internet Explorer (832894).
Verify that there is a lock icon in the lower right Status bar and verify the name of the server that provides the page that you are viewing before you type any personal or sensitive information.
Do not click any hyperlinks that you do not trust. Type them in the Address bar yourself.

Install the MS04-004 Cumulative Security Update for Internet Explorer (832894)

For additional information about this security update, visit the following Microsoft Web site:

http://www.microsoft.com/technet/security/bulletin/MS04-004.mspx

This article also discusses steps that will help you identify spoofed Web sites and malicious hyperlinks.

Note You do not have to install this update if you have already installed Microsoft Windows XP Service Pack 2. The update is included in this service pack.

Things that you can do to help protect yourself from spoofed Web sites

Make sure that the Web site uses Secure Sockets Layer/Transport Layer Security (SSL/TLS) and check the name of the server before you type any sensitive information.

SSL/TLS is typically used to help protect your information as it travels across the Internet by encrypting it. However, it also serves to prove that you are sending data to the correct server. By checking the name on the digital certificate user for SSL/TLS, you can verify the name of the server that provides the page that you are viewing. To do this, verify that the lock icon appears in the lower right corner of the Internet Explorer window.

Note If the status bar is not enabled, the lock will not appear. To enable the Status bar, click View, and then click to select Status Bar.

To verify the name of the server that appears on the digital certificate, double-click the lock icon, and then check the name that appears next to Issued to. If the Web site does not use SSL/TLS, do not send any personal or sensitive information to the site. If the name that appears next to Issued to is different from the name of the site that you thought provides the page that you are viewing, close the browser to leave the site. For additional information about how to do this, visit the following Microsoft Web site:

http://www.microsoft.com/protect/yourself/phishing/spoof.mspx

Things that you can do to help protect yourself from malicious hyperlinks

The most effective step that you can take to help protect yourself from malicious hyperlinks is not to click them. Rather, type the URL of your intended destination in the address bar yourself. By manually typing the URL in the address bar, you can verify the information that Internet Explorer uses to access the destination Web site. To do so, type the URL in the Address bar, and then press ENTER.

Note The Address bar does not appear if it is not enabled. To enable the Address bar, click View, point to Toolbars, and then click to select Address Bar.

Some things that you can do to identify spoofed sites when the Web site is not using SSL/TLS

The most effective step that you can take to verify the name of the site that provides the page that you are viewing is to verify the name on a digital certificate using SSL/TLS. But if the site does not use SSL/TLS, you cannot conclusively verify the name of the site that provides the page that you are viewing. However, there are some things that you can do that, in some cases, may help you identify spoofed sites.

Caution The following information provides general guidelines based on well-known attacks. Because attacks change constantly, malicious users could create spoofed Web sites by using means other than those that are described here. To help protect yourself, type personal or sensitive information on a Web site only if you have verified the name on the digital certificate. Also, if you have any reason to suspect the authenticity of a site, leave it by closing the browser window immediately. Frequently, the quickest way to close the browser window is to press ALT+F4.

Try to identify the URL of the current Web page

To try to identify the URL of the current Web site, use the following methods.

Use Jscript commands to try to identify the actual URL for the current Web site

Use a JScript command in Internet Explorer. In the Address bar, type the following command, and then press ENTER:

javascript:alert("Actual URL address: " + location.protocol + "//" + location.hostname + "/");

Caution Use caution when you type script directly in the Address bar. Script that you type directly in the Address bar can take the same actions on the local system as the user who is currently logged on.

The JScript message box shows the actual URL Web address for the Web site that you are visiting.

You can also copy the following JScript code and paste it in the Address bar for a more verbose description of the Web site URL:

javascript:alert("The actual URL is:\t\t" + location.protocol + "//" + location.hostname + "/" + "\nThe address URL is:\t\t" + location.href + "\n" + "\nIf the server names do not match, this may be a spoof.");

Compare the actual URL with the URL in the Address bar. If they do not match, the Web site is likely misrepresenting itself. In this case, you may want to close Internet Explorer.

Use the Internet Explorer History pane to try to identify the actual URL for the current Web site

In the scenarios that Microsoft has tested, you can also use the History Explorer Bar in Internet Explorer to help identify the URL of a Web page. On the View menu, point to Explorer Bar, and then click History. Compare the URL in the Address bar with the URL that appears in the History bar. If they do not match, the Web site is likely misrepresenting itself and you may want to close Internet Explorer.

Paste the URL in the Address bar of a new instance of Internet Explorer

You can paste the URL in the Address bar of a new instance of Internet Explorer. By doing so, you may be able to verify the information that Internet Explorer will use to access the destination Web site. In the scenarios that Microsoft has tested, you can copy the URL that appears in the Address bar and paste it in the address bar of a new session of Internet Explorer to verify the information Internet Explorer will actually use to access the destination Web site. This process is similar to the step that is discussed in “Things that you can do to help protect yourself from spoofed Web sites” section earlier in this article.

Caution If you perform this action on some sites, such as on e-commerce sites, the action can potentially cause your current session to be lost. For example, the contents of an online shopping cart may be lost, and you may have to repopulate the cart.

To paste the URL in the Address bar of a new instance of Internet Explorer, follow these steps:

Select the text in the Address bar, right-click the text, and then click Copy.
Close Internet Explorer.
Start Internet Explorer.
Click in the Address bar, right-click, and then click Paste.
Press ENTER.

Some things that you can do to identify malicious hyperlinks

The only way that you can verify the information that Internet Explorer will use to access the destination Web site is by manually typing the URL in the address bar. However, there are some things that you can do that, in some cases, may help you identify a malicious hyperlink.

Caution The following information provides general guidelines based on well-known attacks. Because attacks change constantly, malicious users could create spoofed Web sites by using means other than those that are described here. To help protect yourself, type personal or sensitive information on a Web site only if you have verified the name on the digital certificate. Also, if you have any reason to suspect the authenticity of a site, leave it by closing the browser window immediately. Frequently, the quickest way to close the browser window is to press ALT+F4.

Try to identify the URL that a hyperlink will use

To try to identify the URL that a hyperlink will use, follow these steps:

Right-click the link, and then click Copy Shortcut.
Click Start, and then click Run.
Type notepad, and then click OK.
On the Edit menu in Notepad, click Paste.

By doing this, you can see the full URL for any hyperlink and you can examine the address that Internet Explorer will use. The following list shows some of the characters that may appear in a URL that could lead to a spoofed Web site:

%00
%01
@

For example, a URL of the following form will open http://example.com, but the URL in the Address bar or the Status bar in Internet Explorer may appear as http://www.wingtiptoys.com:

http://www.wingtiptoys.com%01@example.com

Other steps that you can take

Although these actions do not help you to identify a deceptive (spoofed) Web site or URL, they can help limit the damage from a successful attack from a spoofed Web site or a malicious hyperlink. However, they restrict e-mail messages and Web sites in the Internet zone from running scripts, ActiveX Controls, and other potentially damaging content.

Use your Web content zones to help prevent Web sites that are in the Internet zone from running scripts, running ActiveX Controls, or running other damaging content on your computer. First, set your Internet zone security level to High in Internet Explorer. To do so, follow these steps:
1. On the Tools menu, click Internet Options.
2. Click the Security tab, click Internet, and then click Default level.
3. Move the slider to High, and then click OK.
Next, add the URLs for Web sites that you trust to the Trusted Sites zone. To do so, follow these steps:
1. On the Tools menu, click Internet Options.
2. Click the Security tab.
3. Click Trusted sites.
4. Click Sites.
5. If the sites that you want to add do not require server verification, click to clear the Require server verification (https:) for all sites in this zone check box.
6. Type the address of the Web site you want to add to the Trusted sites list.
7. Click Add.
8. Repeat steps 6 and 7 for each Web site that you want to add.
9. Click OK two times.
Read E-mail Messages in Plain Text.

For Outlook 2002 and Outlook 2003:

307594 OL2002: Users Can Read Nonsecure E-mail as Plain Text

831607 How to View All E-Mail Messages in Plain Text Format in Outlook 2003

For Outlook Express 6:

291387 OLEXP: Using Virus Protection Features in Outlook Express 6

By reading e-mail in plain text, you can see the full URL of any hyperlink and examine the address that Internet Explorer will use. The following are some of the characters that may appear in a URL that could lead to a spoofed Web site:
- %00
- %01
- @
For example, a URL of the following form will open http://example.com, but the URL that appears in the Address bar of Internet Explorer may show http://www.wingtiptoys.com:

http://www.wingtiptoys.com%01@example.com

REFERENCES

For more information about Uniform Resource Locators (URLs), visit the following Word Wide Web Consortium Web site:

http://www.w3.org/Addressing/URL/url-spec.txt

Microsoft provides third-party contact information to help you find technical support. This contact information may change without notice. Microsoft does not guarantee the accuracy of this third-party contact information.

Additional query words: IE URL obfuscation hoax joke trick scam hacker

Keywords: kbinfo kburgent kbsecvulnerability kbsecurity kbsecbulletin kbsechack KB833786

Microsoft KB Archive/833786

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