Intrusion Attempt Who's Knocking Your Door

Transcription

1 10 Intrusion Attempt Who's Knocking Your Door By Kilausuria binti Abdullah Introduction: An intrusion attempt is a potential for a deliberate unauthorized attempt to enter either a computer, system or network to access information and manipulate information or render a system unreliable or unusable. Even though security parameters are built around a home that is equipped with the current or latest security tools, one must also monitor the possibility of someone trying to knock the door down. Despite this, a successful attempt may have hazardous impact not only on a system but also the organization s reputation. Types of Intrusion Attempts: In general, intrusion attempts refer to any activity of someone trying to, or successfully breaching an individual s, entity s or nation s computers. In this report, intrusion attempts are categorized into three forms as follows: 1) Port scanning the act of systematically scanning a computer's communication ports. Since a port is a place where information goes into and out of a computer, port scanning identifies open doors to a computer. Port scanning has legitimate uses in managing networks but can also be malicious in nature if someone is looking for a weakened access point to break into a computer. 2) Login brute force the systematic, exhaustive testing of all possible methods that can be used to break a security system. For example, in cryptanalysis, this entails trying all possible keys in the key space to decrypt a ciphered text, or trying to automate an SSH login (username and password attack). 3) the automated process of proactively identifying possible vulnerabilities of the computing systems in a network in order to determine if and where a system can be exploited and/or threatened. Intrusion attempts are basically received by victims, servers, networks, systems and computers. Such incidents are usually captured in the logfile of the victim s infected machine. For example, the host has performed a complete network scan and is trying to connect to SSH (Secure Shell, TCP port 22) through a user account login service. The incident handler will verify the intrusion attempt log. Once the intrusion attempt log is validated, the incident handler will inform the IP domain/ owner and ISP provider of that particular IP address. The IP domain/owner and ISP provider will subsequently need to verify the intrusion attempt logfiles for further investigation and action. Intrusion Attempt Statistics for Q Table 1: Intrusion Attempts in Q3 (Jul-Sept) 2014

2 In the 3rd quarter of 2014, a total of 902 incidents were reported to CyberSecurity Malaysia under the Intrusion Attempt category as shown in Table 1 and Graph Graph 1: Intrusion Attempts in Q3 (Jul-Sept) 2014 Comparison of Intrusion Attempt Analysis In Quarter , a total of 902 incidents were received in the Intrusion Attempt Report as shown in Table 2 and Graph 2. Intrusion Attempt Report Q3 (Jul-Sept) 2014 Jul Aug Sept TOTAL Port Scanning Login brute force Vulnerability probes TOTAL Table 2: Intrusion Attempts in Q3 (Jul-Sept) 2014 Graph 2: Intrusion Attempts in Q3 (Jul- Sept) 2014 Most intrusion attempt incidents in Q were login brute force, as shown in Table 3 and Graph 3. Type of Intrusion Attempt Total Port Scanning 32 Login brute force Table 3: Total Intrusion Attempt Incidents by Category Note: The statistics reflect the number of incident tickets. Graph 3: Percentage of Intrusion Attempt Incidents by Category From the above graph it can be seen that the majority of intrusion attempt incidents involved are login brute force, representing 96% compared to other intrusion attempt categories. The remaining intrusion attempt categories are port scanning (3%) and vulnerability probes (1%). In the 3rd quarter of 2013, a total of 15 incidents were recorded as Intrusion Attempt Incidents as shown in Table 4 and Graph 4.

3 12 Intrusion Attempt Categories Intrusion Attempt Report Q3 (Jul-Sept) 2013 July Aug Sept TOTAL Port Scanning Login brute force Vulnerability probes TOTAL Table 4: Intrusion Attempts for Q3 (July-Sept) 2013 Note: The statistics reflect the number of incident tickets. The above graph indicates that the majority of intrusion attempt incidents involved port scanning, which represents 60% compared to other categories. The remaining categories are vulnerability probes (27%) and login brute force (13%). According to the statistics above, intrusion attempt incidents from the 3rd quarter 2013 to the 3rd quarter 2014 increased from 15 to 902 cases. In-depth Analysis of Intrusion Attempts in Q In the 3rd quarter of 2014, the major type of intrusion attempts discovered based on the incidents reported is login brute force. The number of intrusion attempts discovered in this quarter are listed in Table 6 and Graph 6 below. Graph 4: Intrusion Attempts for Q3 (July-Sept) 2013 Most of the intrusion attempt incidents for Quarter involved port scanning, as shown in Table 5 and Graph 5. Type of Intrusion Attempt Total Port Scanning 9 Login brute force 2 4 Table 5: Total Incidents of Intrusion Attempts for Q by Category Intrusion Attempt Sub-categories Login brute force -- manually launched Login brute force -- unknown Login brute force -- automatically launched Port scanning -- search open port Port scanning -- unknown -- malware spreading -- manually using tools -- unknown July Aug Sept TOTAL Table 6: Percentage of Intrusion Attempt Incidents by Subcategory Based on analysis for Q3 2014, intrusion attempt incidents under login brute force -- unknown, vulnerability probes -- unknown, had the highest reported number, or 95% of the total reported incidents. This was followed by intrusion attempts on port scanning -- open ports (2%). Intrusion attempts by login brute force -- automatically launched, port scanning -- unknown and vulnerability probes -- unknown, contributed 1% each. Graph 5: Percentage of Intrusion Attempt Incidents for Q by Category

4 13 Graph 6: Percentage of Intrusion Attempt Incidents by Subcategory A total of 902 incidents were reported in the Intrusion Attempt Report for Q These were reported from various organizations and categorized under various intrusion attempt sub-categories. The most frequently reported incidents were from CyberSecurity Malaysia, followed by other Computer Emergency Response Teams (foreign CERT) and other organizations as shown in Table 7 and Graph 7. Reports From TOTAL CyberSecurity Malaysia 843 Foreign Computer Emergency Response Teams 37 Foreign Special Interest Groups 2 Foreign Companies 2 Foreign Educational Organizations 1 Foreign Finance Institutions 4 Local ISP 1 Local Companies 7 Local Finance Institutions 1 Local Security Organizations 1 Foreign Security Organizations 2 Table 7: Figures on Intrusion Attempts Based on Organization Reports Graph 7: Percentage of Intrusion Attempts Based on Organization Reports Most incidents of intrusion attempts reported were by CyberSecurity Malaysia, comprising 94% of the total reported incidents. Foreign Computer Emergency Response Teams (foreign CERT) contributed about 4% while local companies and foreign finance institutions both represented 1% respectively. For Quarter , most intrusion attempt incidents were reported by CyberSecurity Malaysia and were login brute force -- unknown, and port scanning -- unknown. Graph 8: Sub-categories of Intrusion Attempts Based on Organization Reports Table 8: Sub-categories of Intrusion Attempts Based on Organization Reports

5 14 Login Brute Force Description: Login brute force is a password-guessing type of attack of the unauthorized access attempt kind. A brute force attack can be recognized by reviewing the operating system s security log. If such attack happens when an attacker attempts to log in to the system at any time and fails to do so, an event message is written in the operating system s security log. This attempt is generally meant to discover a password by systematically trying every possible combination of letters, numbers, and symbols until the one correct combination that works is discovered. A good target of brute force attacks is a website that requires user authentication. Brute force attacks can put user accounts at risk and also flood sites with unnecessary traffic. These attacks are easy to detect but not so easy to prevent. For example, HTTP brute force tools can relay requests through a list of open proxies. Although each request appears to come from a different IP address, this attack cannot be simply prevented by blocking the IP address. Some tools will try a different username and password on each attempt, therefore a single account cannot be simply locked out for failed password attempts. Impact of Discovered Intrusion Attempts The impact of reported intrusion attempts that can affect systems includes: 1. An attacker may attempt to discover a weak password by systematically trying every possible combination of letters, numbers and symbols until they discover the one correct combination that works. 2. By using port scan tools, attackers could determine a system s weaknesses and the best method for an attack. The negative impact of port scans are numerous and range from wasting resources, to network congestion, and enabling future, more serious attacks. Best Practices/Recommendations for Prevention: There are several techniques to consider for defeating a brute force login attack: Advanced users who want to protect their accounts from attack should be given the option to be allowed to login only from certain IP addresses. Assign unique login URLs to blocks of users, so that not all users can access the site from the same URL. Use a CAPTCHA to prevent automated attacks. Instead of completely locking out an account, place it in lockdown mode with limited capabilities. Well-chosen passwords are effective at defeating brute force login attacks. It is prudent to implement a security policy that requires users to change their passwords on a regular basis. Therefore, it is useful for system administrators and other network defenders to detect login brute force attacks in order to recognize precursors for serious attacks. Conclusion In conclusion, the number of incidents categorized under intrusion attempts during the 3rd Quarter 2014 was 902 tickets. The total incident number increased by 887 from Quarter 3 the previous year. System administrators, Internet service providers (ISPs), Web hosts or regular users must be aware and concerned with intrusion attempt activities that may be present in their systems logs. The repercussions from such intrusion attempts can have high impact on the affected organization, even if few log activities are detected. Attackers will continue repeating the same activities if no additional preventive measures are in place. The kind of response received from login brute force activities could indicate whether the attacker was able to gain access to the system or whether they probed for further weaknesses such as gaining access to account data and obtaining personal information for potentially malicious purposes. System administrators and users for example, must always make sure their computers, systems and servers are regularly having the best security policies implemented, especially for defeating brute force login attacks. References 1. report_incidents/cyber999/main/detail/799/ index.html 2. Blocking_Brute_Force_Attacks 3. reference/vuln/brute_force_login_attack.htm 4. PortScans.pdf