What is Phishing and Pharming?

Phishing attacks use both social engineering and technical subterfuge to steal consumers' personal identity data and financial account credentials. Social-engineering schemes use 'spoofed' e-mails to lead consumers to counterfeit websites designed to trick recipients into divulging financial data such as credit card numbers, account usernames, passwords and social security numbers. Hijacking brand names of banks, e-retailers and credit card companies, phishers often convince recipients to respond. Technical subterfuge schemes plant crimeware onto PCs to steal credentials directly, often using Trojan keylogger spyware. Pharming crimeware misdirects users to fraudulent sites or proxy servers, typically through DNS hijacking or poisoning.

Avoiding Social Engineering and Phishing Attacks

What is a social engineering attack?

To launch a social engineering attack, an attacker uses human interaction (social skills) to obtain or compromise information about an organization or its computer systems. An attacker may seem unassuming and respectable, possibly claiming to be a new employee, repair person, or researcher and even offering credentials to support that identity. However, by asking questions, he or she may be able to piece together enough information to infiltrate an organization's network. If an attacker is not able to gather enough information from one source, he or she may contact another source within the same organization and rely on the information from the first source to add to his or her credibility.

What is a phishing attack?

Phishing is a form of social engineering. Phishing attacks use email or malicious web sites to solicit personal, often financial, information. Attackers may send email seemingly from a reputable credit card company or financial institution that requests account information, often suggesting that there is a problem. When users respond with the requested information, attackers can use it to gain access to the accounts.

How do you avoid being a victim?

• Be suspicious of unsolicited phone calls, visits, or email messages from individuals asking about employees or other internal information. If an unknown individual claims to be from a legitimate organization, try to verify his or her identity directly with the company.
  
  
  
• Do not provide personal information or information about your organization, including its structure or networks, unless you are certain of a person's authority to have the information.
  
  
  
• Do not reveal personal or financial information in email, and do not respond to email solicitations for this information. This includes following links sent in email.
  
  
  
• Don't send sensitive information over the Internet before checking a web site's security policy or looking for evidence that the information is being encrypted (see Protecting Your Privacy and Understanding Web Site Certificates for more information).
  
  
  
• Pay attention to the URL of a web site. Malicious web sites may look identical to a legitimate site, but the URL may use a variation in spelling or a different domain (e.g., .com vs. .net).
  
  
  
• If you are unsure whether an email request is legitimate, try to verify it by contacting the company directly. Do not use contact information provided on a web site connected to the request; instead, check previous statements for contact information. Information about known phishing attacks is also available online from groups such as the Anti-Phishing Working Group (http://www.antiphishing.org/phishing_archive.html).
  
  
  
• Install and maintain anti-virus software, firewalls, and email filters to reduce some of this traffic (see Understanding Firewalls, Understanding Anti-Virus Software, and Reducing Spam for more information).

What do you do if you think you are a victim?

• If you believe you might have revealed sensitive information about your organization, report it to the appropriate people within the organization, including network administrators. They can be alert for any suspicious or unusual activity.
  
  
  
• If you believe your financial accounts may be compromised, contact your financial institution immediately and close any accounts that may have been compromised. Watch for any unexplainable charges to your account (see Preventing and Responding to Identity Theft for more information).
  
  
  
• Consider reporting the attack to the police, and file a report with the Federal Trade Commission (http://www.ftc.gov/).

Warns Public of Fraudulent Phishing Email.

US-CERT is aware of a recent surge in fraudulent phishing e-mail messages. The messages, claiming to be from the United States National Medical Association, contain a subject line that reads "The United States National Medical Association" and a link that, when followed, will direct the user to a malicious website. These messages are not from any United States government agency.

Users are encouraged to take the following measures to protect themselves from phishing attacks:

• Do not follow unsolicited web links received in email messages.


• Verify the legitimacy of the email by contacting the company or agency directly through a trusted contact number.


• Visit the Anti-Phishing Working Group for more information on known phishing attacks.

Mozilla Releases Update to Address URI Sanitization Vulnerability

Mozilla has released an update for the Firefox browser to address two vulnerabilities with URI sanitization.  These vulnerabilities may allow a remote, unauthenticated attacker to execute arbitrary code on an affected system. 

More information regarding these vulnerabilities and the Firefox update can be found in the following:

• Vulnerability Note VU#783400
  
• Vulnerability Note VU#403150
  
• Mozilla Foundation Security Advisory 2007-27
  
• Mozilla Firefox update

US-CERT encourages users to upgrade to Firefox 2.0.0.6 which has been released to address these vulnerabilities.

Microsoft Windows URI Protocol Handling Vulnerability

US-CERT is aware of a vulnerability in the way Microsoft Windows determines how to handle URIs, which may be be leveraged by a remote attacker to execute arbitrary commands on an affected system.  Public reports demonstrate that Mozilla Firefox can be used to pass malicious URIs to Windows, but other applications may also act as attack vectors for this vulnerability.

More information regarding this vulnerability can be found in Vulnerability Note VU#403150.