With IP blocking, when a Cisco IDS detects an attack, it can log into a Cisco PIX or router and add a temporary filtering rule to block the attack. Four general categories of session attacks exist: The following sections cover these session attacks in more depth. To prevent Java and ActiveX attacks on your users, and possibly your web servers, you should use a filtering solution that can filter Java and ActiveX scripts that are embedded in HTML pages. Authentication, Authorization, and Accounting, Part III: Nonstateful Filtering Technologies, Part IV: Stateful and Advanced Filtering Technologies, Chapter 10. Data manipulation is simply the process of a hacker changing information. Systems of interest might include utilities, public safety, transportation systems, financial systems, or defense systems, which are all managed by large data systems, each with vulnerabilities. As an example, if you have a network of 200.200.200.0/24, the hacker would ping 200.200.200.255. Other types of attacks include exploiting weaknesses in operating systems and applications, such as buffer overflows, that can allow a hacker access without first authenticating. All rights reserved. Many, if not most, web sites take advantage of this technology to provide enhanced web features. You also should disable all unnecessary services and consider using a host-based firewall. A large portion of current cyberattacks are professional in nature, and profit-motivated--which is why banks are the favorite target. An example of this attack is discussed earlier in the chapter in the "Unstructured and Structured Threats" section and in Figure 1-2. Cybercriminals are carefully discovering new ways to tap the most sensitive networks in the world. Another solution is to employ a switched infrastructure, giving every device its own switch port connection. Upon receiving the packet, the destination tries to forward the packet to itself. 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. Typically, a hacker uses a protocol analyzer and special software to implement this type of attack. All too often, employers fail to prosecute this type of activity. When the Cisco IOS router or PIX sees a web access request from a user, it first verifies it with the policy server before permitting it. This list is not final – each organization must add their own specific threats … Besides reconnaissance attacks, the second most common form of security threat and attack is the DoS attack. Types of Threats Threats can be classified into four different categories; direct, indirect, veiled, conditional. Typically, most of these attacks are exploited through the e-mail system, although there are other methods, such as executing an infected program. Cybercriminals’ principal goal is to monetise their attacks. A common attack that hackers employ is to break into your web server and change the content (web pages). 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. 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. Spam is one of the most common security threats… One of the most difficult attacks that a hacker can carry out is a session layer attack. It comes with a 30-day trial, after which certain features are disabled unless you purchase the full version. External threats are threats from individuals outside the organization, often using the Internet or dial-up access. An unsophisticated hacker typically sends large messages to your e-mail server, hoping to fill up the disk space and crash it. 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. The age-old WPS threat vector. Unlike bugs, viruses are manmade. A good hacker makes this flood of fragments appear as a set of legitimate connections, which can cause a buffer overrun on the destination and possibly crash the machine. Theft and burglary are two of the most common types of physical security threats, and they are some of the easiest to protect against. Because less than three days had passed since the loss was inadvertently exposed, I was shocked at the coolness and speed of the reaction. a risk that which can potentially harm computer systems and organization You might think that executing this type of attack would be very complicated; however, some protocols, such as TCP, are fairly predictable, especially in their use of sequence numbers for TCP segments. Hackers typically attack such popular applications as Microsoft's IIS web server, web browsers such as Microsoft Internet Explorer and Netscape Navigator, and e-mail applications such as Sendmail and Microsoft Exchange and Outlook because of their widespread use. These use the MD5 hashing algorithm, which creates a unique digital signature that is added to all routing information. 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. Regardless of the type of network security threat, there are different motives for executing network attacks and they are often malicious. Hackers sometimes use Java or ActiveX scripts to create malicious applets. A security event refers to an occurrence during … In an attempt to categorize threats both to understand them better and to help in planning ways to resist them, the following four categories are typically used. The list of Security threats is long and cyber criminality is real. In TCP/IP, this form of an attack is called IP spoofing. ", At the very least, your networking equipment should keep extensive audits and logs to keep track of security issues. Logging is discussed in Chapter 18, "Logging Events.". 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. 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. On some systems, this crashes the device. Released semiannually, the … 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. These attacks are often the result of people with limited integrity and too much time on their hands. Unlike viruses and worms, Trojan horses do not replicate themselves. Now, do not take this the wrong way and think that I am gloating about security threat countermeasures. In an access attack, a hacker attempts to gain unauthorized or illegal access to your network and its resources, particularly resources such as file, e-mail, and web servers. You periodically should compare the critical files on your server to the snapshot that you took previously. In the US, the average cost of a cyberattack in 2017 was $22.21 million dollars. 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. For each of these, we’ve attached … 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. 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. 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). Many scanning tools are available?freeware, shareware, and commercial. I also use a product called Nessus, available at http://www.nessus.org/, and Cisco Scanner (formerly known as NetSonar), available at http://www.cisco.com/univercd/cc/td/doc/pcat/nssq.htm. Obviously, certain network administrators should be allowed to perform eavesdropping in certain situations, such as troubleshooting connectivity issues. With the ability to annoy, harm and steal, these threats masterfully disguise their way into a system by manipulating the users. This is a general category of a DoS attack in which more specific attacks, such as packet fragmentation or chargen, are used. After a hacker has broken into one of your networking devices, he usually tries to raise his privilege level to the highest possible degree and then uses this account to break into other networking devices. The attack might be structured from an external source, but a serious crime might have one or more compromised employees on the inside actively furthering the endeavor. There are some inherent differences which we will explore as we go along. One large advantage of using an IDS is that these can detect reconnaissance attacks and probes, alerting you to the fact that possible hacking problems are looming. The most common form of an e-mail bomb is a virus or worm. Another typical solution for file servers is to use application verification software. Filtering Web and Application Traffic, Part V: Address Translation and Firewalls, Traffic Distribution with Server Load Balancing, Reverse-Path Forwarding (Unicast Traffic), Part VII: Detecting and Preventing Attacks, Chapter 19. 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. Routing protocol protection is discussed in Chapter 15, "Routing Protocol Protection. For instance, the standard Telnet application uses clear-text passwords when performing authentication. Of course, one of the most popular methods of dealing with these kinds of attacks is to deploy antivirus software. The goal of the hacker is to perform repudiation when executing session layer attacks. The networking department did not want to have to change all of the privileged EXEC passwords on the routers every time a contractor left the company. Of course, a network scan tells the hacker only that there are machines in your network with a configured IP address; it does not tell what services are running on these machines. Any other type of eavesdropping by anybody else (other employees), however, should not be tolerated and should be dealt with immediately. The Four Primary Types of Network Threats. Host-based firewalls are discussed in more depth in Chapter 2. Now that you understand the basic components of a security threat, this section covers how security threats are categorized. Earthquakes 2. The solution that you implement to restrict unauthorized access attacks depends on the method the hacker is using to gain unauthorized access. In a session attack, a hacker attacks a session layer connection, hoping either to use this information to mount another attack, or, through subterfuge, to take over the session in which he pretends to be either the source or the destination device. The best method of preventing data-manipulation attacks is to implement a centralized and robust authentication and authorization system, such as Cisco Secure ACS, which is discussed briefly in the previous section. Viruses are the most common threat known to tech users. A difference might indicate that an access attack has taken place, possibly with a worm or Trojan horse attack, and that one of your files has been replaced with a hacker's file. Chargen runs on port 19 and usually is enabled on most operating systems. 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. 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. Denial-of-service (DDoS) aims at shutting down a network or service, causing it to be inaccessible to its intended users. 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. The bottom line is that the bonding company and the dentist came to terms, and I never heard another word about it. This is perhaps one of the biggest complaints of anyone who has an Internet e-mail account; I am constantly getting spam e-mails. The first step in any information security threat assessment is to brainstorm a list of threats. The following sections cover the basics of these types of access attacks. 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. More sophisticated IDS solutions even can interact with your network equipment, such as routers and firewalls, and automatically configure them to filter the offending traffic when it is detected. 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. 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. For file servers, tools are available to take a snapshot of your files, and the snapshot then is stored in a secured location. Structured threats are more focused by one or more individuals with higher-level skills actively working to compromise a system. Therefore, I recommend filtering these scripts only from networks in which known security threats exist. 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. A network scanning attack occurs when a hacker probes the machines in your network. A hacker sends a single ICMP message with an offset field indicating that the data is larger than 65,535 bytes. The last thing you want to do is to unde… If there is a difference, the application alerts you to this. This can be something as simple as using Cisco routers with access control lists or a sophisticated firewall. To protect yourself from malicious applets, you should use a firewall system, such as the Cisco IOS router or PIX, to filter Java and ActiveX scripts and applets. Sometimes a hacker downloads Java or ActiveX scripts to clients that capture web transactions?possibly even online order information such as credit card numbers?and then uses this for his own purposes. Many programs are available on the Internet to perform this process, including Hping (http://www.hping.org/) and Nemesis (http://www.packetfactory.net/Projects/nemesis/), as well as others. 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