Just as hackers use many DoS attacks to hamper your network's performance, you can use many solutions to prevent or at least hinder a hacker's DoS attack. The attackers are typically knowledgeable about network designs, security, access procedures, and hacking tools, and they have the ability to create scripts or applications to further their objectives. Structured threats are more focused by one or more individuals with higher-level skills actively working to compromise a system. Lock-and-key works hand-in-hand with PPP's CHAP. By filtering these scripts and applets, you are reducing the likelihood of a hacker performing a session layer attack. Tracing the culprit in these kinds of attacks can be difficult, especially if the hacker is using many different ISPs as the source of the attack. The most common type of reconnaissance attack is a scanning attack. You typically include files such as executables, batch scripts, and configuration files in this snapshot. With this solution, you can restrict what users can access, restrict what they can do on the service that they access, and record the event for security purposes. The Cisco IOS Firewall feature set supports a feature called Context-based Access Control (CBAC), which implements a firewall system on a router. But as we've seen with retail hacks like TJX, cybercriminals have also figured out how to skim money off any business that handles transactions. Disabling Unnecessary Services, Manual Configuration Example of Disabling Services on a Perimeter Router, Chapter 5. Information about this excellent freeware product can be found at http://www.mailwasher.net/. Unstructured threats often involve unfocused assaults on one or more network systems, often by individuals with limited or developing skills. a risk that which can potentially harm computer systems and organization TCP SYN flood attack In this … This was because every week a new contractor was hired and an old contractor's time was up, and the old contractor moved on to the next job. Eavesdropping is the process of examining packets as they are in transit between a source and destination device. This type of attack has happened to many organizations, typically government resources; a hacker breaks into a web server and replaces the web content with pornography or "interesting" political content. This method of encryption is used on connections that traverse multiple hops, such as internal networks, public networks, and the Internet. Landslides 3. According to the FBI guidelines for workplace security, you should always take special care to address any vulnerabilities pertaining to the internal as well as external threats to save millions of dollars as a business loss. Earthquakes 2. A hacker typically implements a reconnaissance attack that involves the use of a port scanner to discover open ports, and possibly even an eavesdropping attack, using a protocol analyzer, to see the actual traffic flow, including usernames and passwords. Another form of reconnaissance attack is eavesdropping. For more information on common DDoS attacks and tools, visit Dave Dittrich's site at http://staff.washington.edu/dittrich/misc/ddos/. They combine this with a routing attack so that the packets sent to a destination are returned not to the source inside your network, but to the hacker himself. Regardless of the type of network security threat, there are different motives for executing network attacks and they are often malicious. Many packages are available on the market, with the most popular being antivirus software packages from Network Associates and Norton (I use Norton on my PC). The Internet has many sites where the curious can select program codes, such as a virus, worm, or Trojan horse, often with instructions that can be modified or redistributed as is. The following are common solutions used to detect and prevent DoS attacks: Using an intrusion-detection system (IDS), Using routing protocols with authentication, The first solution that you should implement is filtering. As an example, the hacker might cut the source device out of the picture and pretend to be the source, tricking the destination device into believing that the destination still is communicating with the original source. Unstructured attacks involving code that reproduces itself and mails a copy to everyone in the person’s e-mail address book can easily circle the globe in a few hours, causing problems for networks and individuals all over the world. With a DoS attack, a hacker attempts to deny legitimate traffic and user access to a particular resource, or, at the very least, reduce the quality of service for a resource. An enhanced form of DoS attacks are Distributed DoS (DDoS) attacks. This requires excellent technology skills on the hacker's part. So even if the hacker “thought” no one would be hurt, the result is often that they just beat some single parent or new hire out of a day’s pay. Second is the Country Threat List -- a classified list of foreign powers that pose a strategic intelligence threat to U.S. security … The Four Primary Types of Network Threats. By centralizing the authentication process, you have more control over who is accessing your devices and what they are doing on them, making it easier to determine whether unauthorized access attacks are occurring. An apparently useful or amusing program, possibly a game or screensaver, but in the background it could be performing other tasks, such as deleting or changing data, or capturing passwords or keystrokes. Unfortunately, WPS security … You might want to consider replacing your standard Telnet application with a secure one that encrypts the password before sending it across the network, such as SSH. Use double authentication. A true Trojan horse isn’t technically a virus because it doesn’t replicate itself. Structured attacks are more likely to be motivated by something other than curiosity or showing off to one’s peers. One often-neglected prevention method, but one that is easy to implement, is user training. For internal security, you might want to include in your security policy a statement that prohibits eavesdropping, with severe penalties applied. They aren’t alive and they can’t evolve spontaneously from nothing. In the case of a past network employee, even if their account is gone, they could be using a compromised account or one they set up before leaving for just this purpose. The goal of the hacker is to perform repudiation when executing session layer attacks. To highlight our vision of this digital world, here is an unfortunately not exhaustive list of main computer threats. CPU hogging is a type of attack that affects the CPU cycles of a service. I was helping a dentist reconstruct a substantial loss by an office manager when we were all served with papers threatening all sorts of repercussions if we spoke to anyone, including the police, about the matter. Computer security threats are relentlessly inventive. On some systems, this crashes the device. Two basic methods of implementing encryption exist: Link encryption? Obviously, certain network administrators should be allowed to perform eavesdropping in certain situations, such as troubleshooting connectivity issues. Sophisticated hackers use a source IP address that resides inside your network to execute a masquerading attack. In Information Security threats can be many like Software attacks, theft of intellectual property, identity theft, theft of equipment or information, sabotage, and information extortion. Hackers like to use Java or ActiveX scripts, port-scanning utilities, masquerading, and eavesdropping to carry out their repudiation attack. A form of virus that spreads by creating duplicates of itself on other drives, systems, or networks. This client was using the standard user EXEC and privileged EXEC passwords on these devices for authentication. If your router is located at the perimeter of your network, you might want to consider using static routes instead of using a dynamic routing protocol. In the online world, a special third-party device called a Certificate Authority (CA) is used to handle the repository of identities. E-mail delivery methods have replaced “shared” game disks as the vehicle of choice for distributing this type of attack. An unsophisticated hacker typically sends large messages to your e-mail server, hoping to fill up the disk space and crash it. To prevent spamming and e-mail bombs, as well as to reduce the likelihood of a hacker using a public e-mail site to execute a repudiation attack, you should block all e-mail access from public e-mail sites. For instance, if you wanted to set up a connection to a remote site, but you wanted some kind of proof of the remote site's identity, your networking device could get the digital signature of the remote site from the CA and then request the remote site's own digital signature. The hacker then uses this information to execute further attacks, such as DoS or access attacks. You also should disable all unnecessary services and consider using a host-based firewall. There are different types of DoS and DDoS attacks; the most common are TCP SYN flood attack, teardrop attack, smurf attack, ping-of-death attack and botnets. You also might want to configure filters to allow routing update traffic from only certain routing sources; however, if the hacker is smart about this process, he typically changes the source address to match an address that is specified in your allowed list. Performing these tasks on a Cisco router is discussed in Chapter 4. Viruses are the most common threat known to tech users. For more information on DoS attacks, visit http://www.infosyssec.com/infosyssec/secdos1.htm. The solution that you implement to restrict unauthorized access attacks depends on the method the hacker is using to gain unauthorized access. This might mean that some legitimate people might not be able to send you e-mail any longer, but, on the other hand, you are greatly reducing the likelihood of exposure to reconnaissance, DoS, and repudiation attacks against your e-mail system. Four general categories of session attacks exist: The following sections cover these session attacks in more depth. VPNs, which are discussed in Part VIII, "Virtual Private Networks," allow you to use Data Encryption Standard (DES), 3DES, and AES encryption algorithms to protect your data. In the most basic form of an access attack, a hacker tries to gain illegal access to equipment in your network. These changes could be something as simple as modifying file contents on a file server or something as sophisticated as changing packet contents as they are in transit from a source to a destination machine. With a VPN, a hacker cannot see the actual data that is being transferred between the source and destination devices. Unlike viruses and worms, Trojan horses do not replicate themselves. A Trojan horse is a program loaded onto your computer that acts as a benign application, waiting for the user to activate it through normal computer and application activity. My Internet provider constantly scans for these types of e-mails, as does the antivirus software that I run on my PC. For instance, signing electronic documents, transferring money electronically, and buying a product online with your credit card all must have a nonrepudiation process, or else they cannot be legally binding. When executed as a DoS attack, these attacks can affect the CPU cycles, memory, disk space, or bandwidth of a networking device, such as a PC. Cyberes… The protocol analyzer used for eavesdropping, sometimes referred to as a packet sniffer, might be a sophisticated hardware-based protocol analyzer, such as the Network Associates Sniffer products, or it might be a software-based application running on a PC (Network Associates also sells a software-based Sniffer version). Remember, the difference between an unstructured attack and a series of all-out denial-of-service attacks might be that the latter attacker is offended or angry. One of the most common security tools that performs this function is Tripwire, which can be accessed from http://www.tripwire.com/. For application security, if your applications support additional security mechanisms, you definitely should implement them. There are some inherent differences which we will explore as we go along. To see an encyclopedia of viruses, worms, and Trojan horses, visit Symantec's site at http://securityresponse.symantec.com/avcenter/vinfodb.html. Some of these affect the performance of a particular service running on a server, and some drastically can affect the performance of all the machines on a particular network segment. Using this approach, a hacker can determine whether the machine is running SMTP, Telnet, FTP, WWW, or other services. Cybercriminals’ principal goal is to monetise their attacks. Some common terms to be aware of include the following: A program capable of replicating with little or no user intervention, and the replicated programs also replicate. For some applications, you might consider replacing them. These attackers don’t have authorized access to the systems. Theft and burglary are a bundled deal because of how closely they are related. Because Telnet passes this information in clear text, the hacker now knows how to log into the Telnet server, spoofing the identity of the user. For instance, if you have a web server, you should disable services such as Telnet, SMTP, finger, and FTP on it. After a little research, I found this was at least the third dentist in seven years who had been scammed by the same person. This can go the other way, too; the hacker can pretend to be a user and can call a network administrator, acting as if he has forgotten his password. When executed as a reconnaissance attack, these attacks can send your e-mail's address book or your password file back to the hacker. Nature and Accidents 1. A much better and more manageable solution than the one discussed in the previous sidebar is to use a centralized security server; Cisco has one called Cisco Secure ACS. This makes it easy for a hacker to get an e-mail account and hide his activities behind a cloud of anonymity. Reconnaissance attacks come in different types, including the following: The following sections cover the basics of these types of reconnaissance attacks. One of the most difficult attacks that a hacker can carry out is a session layer attack. The bottom of Figure 1-4 shows the actual data path of a hijacked session. Even if the machine does not crash, the hacker is tying up buffer space, which prevents legitimate traffic from being processed. Research conducted by the US Computer Emergency Response Team (Cert) estimates that almost 40 percent of IT security breaches are perpetrated by people inside the company. I once worked with a client that had to manage more than 1000 Cisco routers. International terrorism and government-sponsored attacks on another country’s computer infrastructure are becoming well documented. All rights reserved. One of my favorites, GFI's LANguard Network Security Scanner, is a feature-rich network-scanner tool. Your networking device then would compare the two signatures. Types of Threats Threats can be classified into four different categories; direct, indirect, veiled, conditional. A session-hijacking attack typically involves a handful of other attacks, such as masquerading, eavesdropping, and data manipulation. Many surveys and studies show that internal attacks can be significant in both the number and the size of any losses. Here is the list of all the types of internet threats: Types of Internet Threats A - L. Types of Internet Threats M-Z. Secure Sockets Layer (SSL) provides security in web transactions. Because there are literally hundreds of DoS attacks, the following list is limited to some of the most common ones: An application attack is simply an attack against an application running on a server. As an example, if you have a network of, the hacker would ping In a reconnaissance attack, a hacker tries to gain information about your network, including its topology, the devices that reside inside it, the software running on them, and the configuration that has been applied to these devices. With a good hacking software program, a skilled hacker can insert himself into the middle of an existing connection. Greed, politics, racism (or any intolerance), or law enforcement (ironic) could all be motives behind the efforts. You can use many solutions to prevent session layer attacks against your user and service connections: Probably the most important is using a Virtual Private Network (VPN) to encrypt information going across the connection. A digital signature is similar to a written signature, a person's thumbprint, a retinal scan of a person's eye, or a DNA profile of a person. Generally, a virus is a program or a piece of code that is loaded onto and run on your computer without your knowledge. To make your life easier, your networking devices always should have logging enabled, and they should transfer this logging information to a central repository where you can keep an audit trail of important connections and transaction. While the original intent might have been more thoughtless than malicious, the result can be a loss of user access while systems are being protected, a loss of reputation if the news that a company’s site has been attacked, or a loss of user freedoms as more-restrictive policies and practices are implemented to defend against additional attacks. For instance, if the hacker is trying to gain illegal access to your network through your network's remote access (dialup) server, you probably would want to implement the following solutions: Use the Challenge Handshake Authentication Protocol (CHAP) with PPP (Point-to-Point Protocol), where the password is not sent across the wire, is tied to a specific user, and is verified by a security server. The most common network security threats … In this type of attack, a hacker tries to feed your routers with either bad routing information that will cause your packets to be routed to a dead end, or misinformation that will cause your packets to be routed back to the hacker so that he can perform eavesdropping and use this information to execute another attack. However, for sensitive information, encryption should be used to protect it. The systems being attacked and infected are probably unknown to the perpetrator. If the hacker can compromise both a PC and the switch connected to the PC, the hacker can set up port mirroring, to have the switch mirror traffic from other ports to the port of the compromised PC. You always should encrypt the following types of information: Personal information, such as telephone numbers, medical information, driver's license numbers, and social security numbers, Company trade secrets and sensitive information. Denial-of-service (DDoS) aims at shutting down a network or service, causing it to be inaccessible to its intended users. A security event refers to an occurrence during … In some organizations, if the network is down, entire groups of people can’t do their jobs, so they’re either sent home or they sit and wait without pay because their income is tied to sales. Many, if not most, web sites take advantage of this technology to provide enhanced web features. It is excellent for detecting spam messages and bouncing these back to the sender. This list of threats and vulnerabilities can serve as a help for implementing risk assessment within the framework of ISO 27001 or ISO 22301. The reasons range from fear of the activity becoming public knowledge to knowing that, quite often, record-keeping systems haven’t been developed either to provide adequate evidence or to prove that the transactions, no matter how ludicrous, weren’t authorized. But like most of these digital threats, the most effective way to combat these pests is to prevent them from affecting your computer in the first place! When a hacker executes a session-replay attack, he captures (actually, eavesdrops on) packets from a real session data transfer between two devices with a protocol analyzer. Cisco has a range of IDS solutions, which enable you to implement a feature called IP blocking or shunning. Unlike bugs, viruses are manmade. The next section discusses some other solutions to e-mail bombs. The age-old WPS threat vector. A ping of death attack is one of my favorite attacks because of its simplistic beauty. A common attack that hackers employ is to break into your web server and change the content (web pages). Many commercial, shareware, and freeware protocol-analyzer products are available. For file servers, tools are available to take a snapshot of your files, and the snapshot then is stored in a secured location. WinNuke is a program that was developed to take advantage of a bug in certain versions of Microsoft operating systems, including 95, 98, Me, XP, NT, and 2000. A direct threat identifies a specific target and is delivered in a straightforward, clear, and … Another favorite method of hackers is to use cookies to masquerade as a site, and then to get the client device to believe that the hacker's computer is the real web destination. Because encryption is very process intensive, it typically is used for external connections; in other words, it typically is not used inside your network. 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This tool is for end-user use only ; you also should disable all unnecessary services Manual! At shutting down a network or service, causing it to be a different machine by changing his source and. Your packets for instance, you definitely should implement them of their resources fighting this mirroring process SPAN short. Classifies the traffic as either an attack your password file back to the sender, encryption should be with! Any suspicious e-mail should be reported immediately to a network administrator there is a router or firewall that can Java... ``, at a later time you should warn your users never open... The number and the size of any losses online world, here is an access.. Names to IP addresses network scanning attack services use the MD5 hashing,. Typically include files such as packet fragmentation and reassembly attack, a hacker typically uses a protocol and! With the ability to annoy, steal and harm router is discussed in 17.