Benefits and Risks of Free Email Services

What is the appeal of free email services?

Many service providers offer free email accounts (e.g., Yahoo!, Hotmail, Gmail). These email services typically provide you with a browser interface to access your mail. In addition to the monetary savings, these services often offer other benefits:

• accessibility - Because you can access your account(s) from any computer, these services are useful if you cannot be near your computer or are in the process of relocating and do not have an ISP. Even if you are able to access your ISP-based email account remotely, being able to rely on a free email account is ideal if you are using a public computer or a shared wireless hot spot and are concerned about exposing the details of your primary account.
• competitive features - With so many of these service providers competing for users, they now offer additional features such as large amounts of storage, spam filtering, virus protection, and enhanced fonts and graphics.
• additional capabilities - It is becoming more common for service providers to package additional software or services (e.g., instant messaging) with their free email accounts to attract customers.

Free email accounts are also effective tools for reducing the amount of spam you receive at your primary email address. Instead of submitting your primary address when shopping online, requesting services, or participating in online forums, you can set up a free secondary address to use (see Reducing Spam for more information).

What risks are associated with free email services?

Although free email services have many benefits, you should not use them to send sensitive information. Because you are not paying for the account, the organization may not have a strong commitment to protecting you from various threats or to offering you the best service. Some of the elements you risk are

• security - If your login, password, or messages are sent in plain text, they may easily be intercepted. If a service provider offers SSL encryption, you should use it. You can find out whether this is available by looking for a "secure mode" or by replacing the "http:" in the URL with "https:" (see Protecting Your Privacy for more information).
• privacy - You aren't paying for your email account, but the service provider has to find some way to recover the costs of providing the service. One way of generating revenue is to sell advertising space, but another is to sell or trade information. Make sure to read the service provider's privacy policy or terms of use to see if your name, your email address, the email addresses in your address book, or any of the information in your profile has the potential of being given to other organizations (see Protecting Your Privacy for more information). If you are considering forwarding your work email to a free email account, check with your employer first. You do not want to violate any established security policies.
• reliability - Although you may be able to access your account from any computer, you need to make sure that the account is going to be available when you want to access it. Familiarize yourself with the service provider's terms of service so that you know exactly what they have committed to providing you. For example, if the service ends or your account disappears, can you retrieve your messages? Does the service provider give you the ability to download messages that you want to archive onto your machine? Also, if you happen to be in a different time zone than the provider, you may find that their server maintenance interferes with your normal email routine.

Shopping Safely Online

Why do online shoppers have to take special precautions?

The internet offers a convenience that is not available from any other shopping outlet. From the comfort of your home, you can search for items from countless vendors, compare prices with a few simple mouse clicks, and make purchases without waiting in line. However, the internet is also convenient for attackers, giving them multiple ways to access the personal and financial information of unsuspecting shoppers. Attackers who are able to obtain this information may use it for their own financial gain, either by making purchases themselves or by selling the information to someone else.

How do attackers target online shoppers?

There are three common ways that attackers can take advantage of online shoppers:

• Targeting vulnerable computers - If you do not take steps to protect your computer from viruses or other malicious code, an attacker may be able to gain access to your computer and all of the information on it. It is also important for vendors to protect their computers to prevent attackers from accessing customer databases.
• Creating fraudulent sites and email messages - Unlike traditional shopping, where you know that a store is actually the store it claims to be, attackers can create malicious websites that appear to be legitimate or email messages that appear to have been sent from a legitimate source. Charities may also be misrepresented in this way, especially after natural disasters or during holiday seasons. Attackers create these malicious sites and email messages to try to convince you to supply personal and financial information.
• Intercepting insecure transactions - If a vendor does not use encryption, an attacker may be able to intercept your information as it is being transmitted.

How can you protect yourself?

• Use and maintain anti-virus software, a firewall, and anti-spyware software - Protect yourself against viruses and Trojan horses that may steal or modify the data on your own computer and leave you vulnerable by using anti-virus software and a firewall (see Understanding Anti-Virus Software and Understanding Firewalls for more information). Make sure to keep your virus definitions up to date. Spyware or adware hidden in software programs may also give attackers access to your data, so use a legitimate anti-spyware program to scan your computer and remove any of these files (see Recognizing and Avoiding Spyware for more information).
• Keep software, particularly your web browser, up to date - Install software updates so that attackers cannot take advantage of known problems or vulnerabilities (see Understanding Patches for more information). Many operating systems offer automatic updates. If this option is available, you should enable it.
• Evaluate your software's settings - The default settings of most software enable all available functionality. However, attackers may be able to take advantage of this functionality to access your computer (see Evaluating Your Web Browser's Security Settings and the paper Securing Your Web Browser for more information). It is especially important to check the settings for software that connects to the internet (browsers, email clients, etc.). Apply the highest level of security available that still gives you the functionality you need.
• Do business with reputable vendors - Before providing any personal or financial information, make sure that you are interacting with a reputable, established vendor. Some attackers may try to trick you by creating malicious websites that appear to be legitimate, so you should verify the legitimacy before supplying any information (see Avoiding Social Engineering and Phishing Attacks and Understanding Web Site Certificates for more information). Attackers may obtain a site certificate for a malicious website to appear more authentic, so review the certificate information, particularly the "issued to" information. Locate and note phone numbers and physical addresses of vendors in case there is a problem with your transaction or your bill.
• Take advantage of security features - Passwords and other security features add layers of protection if used appropriately (see Choosing and Protecting Passwords and Supplementing Passwords for more information).
• Be wary of emails requesting information - Attackers may attempt to gather information by sending emails requesting that you confirm purchase or account information (see Avoiding Social Engineering and Phishing Attacks for more information). Legitimate businesses will not solicit this type of information through email. Do not provide sensitive information through email, and use caution when clicking on links in email messages (see the paper Recognizing and Avoiding Email Scans for more information).
• Check privacy policies - Before providing personal or financial information, check the website's privacy policy. Make sure you understand how your information will be stored and used (see Protecting Your Privacy for more information).
• Make sure your information is being encrypted - Many sites use SSL, or secure sockets layer, to encrypt information. Indications that your information will be encrypted include a URL that begins with "https:" instead of "http:" and a padlock icon. If the padlock is closed, the information is encrypted. The location of the icon varies by browser; for example, it may be to the right of the address bar or at the bottom of the window. Some attackers try to trick users by adding a fake padlock icon, so make sure that the icon is in the appropriate location for your browser.
• Use a credit card - There are laws to limit your liability for fraudulent credit card charges, and you may not have the same level of protection for your debit card. Additionally, because a debit card draws money directly from your bank account, unauthorized charges could leave you with insufficient funds to pay other bills. You can further minimize damage by using a single credit card with a low credit line for all of your online purchases.
• Check your statements - Keep a record of your purchases and copies of confirmation pages, and compare them to your bank statements. If there is a discrepancy, report it immediately (see Preventing and Responding to Identity Theft for more information).

Risks of File-Sharing Technology

What is file sharing?

File sharing involves using technology that allows internet users to share files that are housed on their individual computers. Peer-to-peer (P2P) applications, such as those used to share music files, are some of the most common forms of file-sharing technology. However, P2P applications introduce security risks that may put your information or your computer in jeopardy.

What risks does file-sharing technology introduce?

• Installation of malicious code - When you use P2P applications, it is difficult, if not impossible, to verify that the source of the files is trustworthy. These applications are often used by attackers to transmit malicious code. Attackers may incorporate spyware, viruses, Trojan horses, or worms into the files. When you download the files, your computer becomes infected (see Recognizing and Avoiding Spyware and Recovering from Viruses, Worms, and Trojan Horses for more information).
• Exposure of sensitive or personal information - By using P2P applications, you may be giving other users access to personal information. Whether it's because certain directories are accessible or because you provide personal information to what you believe to be a trusted person or organization, unauthorized people may be able to access your financial or medical data, personal documents, sensitive corporate information, or other personal information. Once information has been exposed to unauthorized people, it's difficult to know how many people have accessed it. The availability of this information may increase your risk of identity theft (see Protecting Your Privacy and Avoiding Social Engineering and Phishing Attacks for more information).
• Susceptibility to attack - Some P2P applications may ask you to open certain ports on your firewall to transmit the files. However, opening some of these ports may give attackers access to your computer or enable them to attack your computer by taking advantage of any vulnerabilities that may exist in the P2P application. There are some P2P applications that can modify and penetrate firewalls themselves, without your knowledge.
• Denial of service - Downloading files causes a significant amount of traffic over the network. This activity may reduce the availability of certain programs on your computer or may limit your access to the internet (see Understanding Denial-of-Service Attacks for more information).
• Prosecution - Files shared through P2P applications may include pirated software, copyrighted material, or pornography. If you download these, even unknowingly, you may be faced with fines or other legal action. If your computer is on a company network and exposes customer information, both you and your company may be liable.

How can you minimize these risks?

The best way to eliminate these risks is to avoid using P2P applications. However, if you choose to use this technology, you can follow some good security practices to minimize your risk:

• use and maintain anti-virus software - Anti-virus software recognizes and protects your computer against most known viruses. However, attackers are continually writing new viruses, so it is important to keep your anti-virus software current (see Understanding Anti-Virus Software for more information).
• install or enable a firewall - Firewalls may be able to prevent some types of infection by blocking malicious traffic before it can enter your computer (see Understanding Firewalls for more information). Some operating systems actually include a firewall, but you need to make sure it is enabled.

Recovering from Viruses, Worms, and Trojan Horses

How do you know your computer is infected?

Unfortunately, there is no particular way to identify that your computer has been infected with malicious code. Some infections may completely destroy files and shut down your computer, while others may only subtly affect your computer's normal operations. Be aware of any unusual or unexpected behaviors. If you are running anti-virus software, it may alert you that it has found malicious code on your computer. The anti-virus software may be able to clean the malicious code automatically, but if it can't, you will need to take additional steps.

What can you do if you are infected?

1. Minimize the damage - If you are at work and have access to an IT department, contact them immediately. The sooner they can investigate and clean your computer, the less damage to your computer and other computers on the network. If you are on your home computer or a laptop, disconnect your computer from the internet. By removing the internet connection, you prevent an attacker or virus from being able to access your computer and perform tasks such as locating personal data, manipulating or deleting files, or using your computer to attack other computers.
2. Remove the malicious code - If you have anti-virus software installed on your computer, update the virus definitions (if possible), and perform a manual scan of your entire system. If you do not have anti-virus software, you can purchase it at a local computer store (see Understanding Anti-Virus Software for more information). If the software can't locate and remove the infection, you may need to reinstall your operating system, usually with a system restore disk that is often supplied with a new computer. Note that reinstalling or restoring the operating system typically erases all of your files and any additional software that you have installed on your computer. After reinstalling the operating system and any other software, install all of the appropriate patches to fix known vulnerabilities (see Understanding Patches for more information).

How can you reduce the risk of another infection?

Dealing with the presence of malicious code on your computer can be a frustrating experience that can cost you time, money, and data. The following recommendations will build your defense against future infections:

• use and maintain anti-virus software - Anti-virus software recognizes and protects your computer against most known viruses. However, attackers are continually writing new viruses, so it is important to keep your anti-virus software current (see Understanding Anti-Virus Software for more information).
• change your passwords - Your original passwords may have been compromised during the infection, so you should change them. This includes passwords for web sites that may have been cached in your browser. Make the passwords difficult for attackers to guess (see Choosing and Protecting Passwords for more information).
• keep software up to date - Install software patches so that attackers can't take advantage of known problems or vulnerabilities (see Understanding Patches for more information). Many operating systems offer automatic updates. If this option is available, you should enable it.
• install or enable a firewall - Firewalls may be able to prevent some types of infection by blocking malicious traffic before it can enter your computer (see Understanding Firewalls for more information). Some operating systems actually include a firewall, but you need to make sure it is enabled.
• use anti-spyware tools - Spyware is a common source of viruses, but you can minimize the number of infections by using a legitimate program that identifies and removes spyware (see Recognizing and Avoiding Spyware for more information).
• follow good security practices - Take appropriate precautions when using email and web browsers so that you reduce the risk that your actions will trigger an infection (see other US-CERT security tips for more information).

As a precaution, maintain backups of your files on CDs or DVDs so that you have saved copies if you do get infected again.

Malware Targeting Point of Sale Systems

Systems Affected

Point of Sale Systems

Overview

Point of Sale Systems
When consumers purchase goods or services from a retailer, the transaction is processed through what are commonly referred to as Point of Sale (POS) systems. POS systems consist of the hardware (e.g. the equipment used to swipe a credit or debit card and the computer or mobile device attached to it) as well as the software that tells the hardware what to do with the information it captures.
When consumers use a credit or debit card at a POS system, the information stored on the magnetic stripe of the card is collected and processed by the attached computer or device. The data stored on the magnetic stripe is referred to as Track 1 and Track 2 data. Track 1 data is information associated with the actual account; it includes items such as the cardholder’s name as well as the account number. Track 2 data contains information such as the credit card number and expiration date.

Description

POS Targeting
For quite some time, cyber criminals have been targeting consumer data entered in POS systems. In some circumstances, criminals attach a physical device to the POS system to collect card data, which is referred to as skimming. In other cases, cyber criminals deliver malware which acquires card data as it passes through a POS system, eventually exfiltrating the desired data back to the criminal. Once the cybercriminal receives the data, it is often trafficked to other suspects who use the data to create fraudulent credit and debit cards.
As POS systems are connected to computers or devices, they are also often enabled to access the internet and email services. Therefore malicious links or attachments in emails as well as malicious websites can be accessed and malware may subsequently be downloaded by an end user of a POS system. The return on investment is much higher for a criminal to infect one POS system that will yield card data from multiple consumers.

Impact

There are several types of POS malware in use, many of which use a memory scraping technique to locate specific card data. Dexter, for example, parses memory dumps of specific POS software related processes looking for Track 1 and Track 2 data. Stardust, a variant of Dexter not only extracts the same track data from system memory, it also extracts the same type of information from internal network traffic. Researchers surmise that Dexter and some of its variants could be delivered to the POS systems via phishing emails or the malicious actors could be taking advantage of default credentials to access the systems remotely, both of which are common infection vectors. Network and host based vulnerabilities, such as weak credentials accessible over Remote Desktop, open wireless networks that include a POS machine and physical access (unauthorized or misuse) are all also candidates for infection.

Solution

POS System Owner Best Practices
Owners and operators of POS systems should follow best practices to increase the security of POS systems and prevent unauthorized access.

• Use Strong Passwords: During the installation of POS systems, installers often use the default passwords for simplicity on initial setup. Unfortunately, the default passwords can be easily obtained online by cybercriminals. It is highly recommended that business owners change passwords to their POS systems on a regular basis, using unique account names and complex passwords.
• Update POS Software Applications: Ensure that POS software applications are using the latest updated software applications and software application patches. POS systems, in the same way as computers, are vulnerable to malware attacks when required updates are not downloaded and installed on a timely basis.
• Install a Firewall: Firewalls should be utilized to protect POS systems from outside attacks. A firewall can prevent unauthorized access to, or from, a private network by screening out traffic from hackers, viruses, worms, or other types of malware specifically designed to compromise a POS system.
• Use Antivirus: Antivirus programs work to recognize software that fits its current definition of being malicious and attempts to restrict that malware’s access to the systems. It is important to continually update the antivirus programs for them to be effective on a POS network.
• Restrict Access to Internet: Restrict access to POS system computers or terminals to prevent users from accidentally exposing the POS system to security threats existing on the internet. POS systems should only be utilized online to conduct POS related activities and not for general internet use.
• Disallow Remote Access: Remote access allows a user to log into a system as an authorized user without being physically present. Cyber Criminals can exploit remote access configurations on POS systems to gain access to these networks. To prevent unauthorized access, it is important to disallow remote access to the POS network at all times.

Consumer Remediation
Fraudulent charges to a credit card can often be remediated quickly by the issuing financial institution with little to no impact on the consumer. However, unauthorized withdrawals from a debit card (which is tied to a checking account) could have a cascading impact to include bounced checks and late-payment fees.
Consumers should routinely change debit card PINs. Contact or visit your financial institutions website to learn more about available fraud liability protection programs for your debit and credit card accounts. Some institutions offer debit card protections similar to or the same as credit card protections.
If consumers have a reason to believe their credit or debit card information has been compromised, several cautionary steps to protect funds and prevent identity theft include changing online passwords and PINs used at ATMs and POS systems; requesting a replacement card; monitoring account activity closely; and placing a security freeze on all three national credit reports (Equifax, Experian and TransUnion). A freeze will block access to your credit file by lenders you do not already do business with. Under federal law, consumers are also entitled to one free copy of their credit report every twelve months through AnnualCreditReport.com.

DOS(Denial of Service) or DDOS(Distributed denial of service ) Attacks working and Pervention from it.

What is mean by DOS(Denial Of Service) or DDOS(Distributed Denial Of Service) Attacks?
denial-of-service (DoS) or distributed denial-of-service (DDoS) attack is an attempt to make a machine or network resource unavailable to its intended users. Although the means to carry out, motives for, and targets of a DoS attack may vary, it generally consists of efforts to temporarily or indefinitely interrupt or suspend services of a host connected to the Internet. As clarification, DDoS (Distributed Denial of Service) attacks are sent by two or more persons, or bots. (See botnet) DoS (Denial of Service) attacks are sent by one person or system.

What is a distributed denial-of-service (DDoS) attack?

In a distributed denial-of-service (DDoS) attack, an attacker may use your computer to attack another computer. By taking advantage of security vulnerabilities or weaknesses, an attacker could take control of your computer. He or she could then force your computer to send huge amounts of data to a website or send spam to particular email addresses. The attack is "distributed" because the attacker is using multiple computers, including yours, to launch the denial-of-service attack.

How do you avoid being part of the problem?

Unfortunately, there are no effective ways to prevent being the victim of a DoS or DDoS attack, but there are steps you can take to reduce the likelihood that an attacker will use your computer to attack other computers:

• Install and maintain anti-virus software (see Understanding Anti-Virus Software for more information).
• Install a firewall, and configure it to restrict traffic coming into and leaving your computer (see Understanding Firewalls for more information).
• Follow good security practices for distributing your email address (see Reducing Spam for more information). Applying email filters may help you manage unwanted traffic.

How do you know if an attack is happening?

Not all disruptions to service are the result of a denial-of-service attack. There may be technical problems with a particular network, or system administrators may be performing maintenance. However, the following symptoms could indicate a DoS or DDoS attack:

• unusually slow network performance (opening files or accessing websites)
• unavailability of a particular website
• inability to access any website
• dramatic increase in the amount of spam you receive in your account

What do you do if you think you are experiencing an attack?

Even if you do correctly identify a DoS or DDoS attack, it is unlikely that you will be able to determine the actual target or source of the attack. Contact the appropriate technical professionals for assistance.

• If you notice that you cannot access your own files or reach any external websites from your work computer, contact your network administrators. This may indicate that your computer or your organization's network is being attacked.
• If you are having a similar experience on your home computer, consider contacting your internet service provider (ISP). If there is a problem, the ISP might be able to advise you of an appropriate course of action.

Session Hijacking How it happens Tips for it and how to avoid it

Session hijacking sometimes called as cookie hijacking.

If hackers hack your computer then he/she easily see the cookies on your computer in that cookies your username and password is stored and hacker can easily decode it.

How TCP session hijacking is done?
First of all learn something How TCP works like explaining below to understand the session.
TCP 3-way Handshaking Connection.
1. Step 1 - SYN
When a workstation wants to communicate with a server it builds a packet with
the SYN or synchronization bit set and then sends the packet to the server. Included in this
SYN packet is an initial sequence number When the client computer generates the sequence number, it uses a random number generator. Random number generators are used to help prevent communication sessions from being compromised (more on this in the next section). Sequence numbers are critical to network communications as they are used to guarantee packet delivery. Source computers use sequence numbers for tracking incoming packets and reassembling them as they arrive
at their destination. From the attacker’s perspective; however, the ability to predict sequence
numbers provides the mechanisms needed to successfully hijack a communication session.


2. Step 2 – SYN/ACK
When the server receives the clients SYN (synchronization) packet, it responds to the
workstation computer with a packet containing both the SYN and ACK (Synchronization and
Acknowledgement) bits set. The packet includes the server’s own randomly generated
sequence number (represented in the drawing by the letter P). The server also acknowledges
the clients sequence number by adding 1 to the sequence number sent by the client computer
(X + 1).
 
3. Step 3 - ACK.
The final phase of the three-way-handshake involves the client sending an ACK packet to the server confirming its desire to communicate. The workstation prepares a packet with the ACK (acknowledgement) bit set and includes an acknowledgement sequence number (X+ 1). When the packet arrives at the destination server, the communication session is established and communication can now begin. An active communication session will be maintained until one of the machines sends a RST (Reset) or FIN (Finish) packet to the other
computer

A popular method is using source-routed IP packets. This allows a hacker at point A on the network to participate in a conversation between B and C by encouraging the IP packets to pass through its machine.
If source-routing is turned off, the hacker can use "blind" hijacking(, whereby it guesses the responses of the two machines. Thus, the hacker can send a command, but can never see the response. However, a common command would be to set a password allowing access from somewhere else on the net.
A hacker can also be "inline" between B and C using a sniffing program to watch the conversation. This is known as a "man-in-the-middle attack".


A common component of such an attack is to execute a denial-of-service (DoS) attack against one end-point to stop it from responding. This attack can be either against the machine to force it to crash, or against the network connection to force heavy packet loss. 

 What Makes the Attack so Dangerous?
Why is the session hijack attack so dangerous? Should security professionals really be concerned? the risks resulting from session hijack attacks can not be eliminated by software patches, complex passwords, or multi-factor authentication. The root cause of the attack lies with design limitations inherent to the TCP/IP protocol. In addition, all machines regardless of operating system or hardware architecture are vulnerable to the session hijack attack provided they are running TCP/IP.
The attacker has the ability to read and modify data, violating the confidentiality and integrity portion of the model. Availability is also affected by the session
hijack attack due to ARP storms and denial of service conditions that are a byproduct of the attack.

Detecting Session Hijack Attacks
There are two primary technologies that assist in session hijack detection. The more manual of the two methods is packet sniffing software which can be used to scan for signatures of an attack. Intrusion detection systems (IDS) and intrusion prevention systems (IPS) provide a more automated method of detection, but they can also create more analysi work for the security administrator.Session hijack attacks are very difficult to detect on busy networks. There are tell tale signs, like computers getting disconnected from the network or periodic network congestion, but these signs usually get ignored by users as “typical network problems”. There are several steps a network administrator can take to preemptively protect their network. Remember,
defense in depth is critical to an effective security plan, and when possible, multiple layers of protection should be implemented.