CCNA Cybersecurity Operations (Version 1.1) – CyberOps Chapter 12 Exam Answers 2019
Which statement describes the status after the Security Onion VM is started?
- Pullpork is used by ELSA as an open source search engine.
- Snort is enabled by default.
- Awk becomes enabled via the sudo awk terminal command.
- SGUIL becomes enabled via the sudo sguil -e terminal command.
Security Onion is a Linux distro for intrusion detection, network security monitoring, and log management. It contains many security tools like Snort, Suricata, Bro, and ELSA.
Which tool is included with Security Onion that is used by Snort to automatically download new rules?
PulledPork is a rule management utility included with Security Onion to automatically download rules for Snort.
What is indicated by a Snort signature ID that is below 3464?
- The SID was created by members of EmergingThreats.
- The SID was created by Sourcefire and distributed under a GPL agreement.
- The SID was created by the Snort community and is maintained in Community Rules.
- This is a custom signature developed by the organization to address locally observed rules.
Snort is an open source network intrusion prevention system (NIPS) and network intrusion detection system (NIDS) developed by Sourcefire. It has the ability to perform real time traffic analysis and packet logging on Internet Protocol (IP) networks and can also be used to detect probes or attacks.
Which tool is a Security Onion integrated host-based intrusion detection system?
OSSEC is a host-based intrusion detection system (HIDS) that is integrated into Security Onion and actively monitors host system operation.
What is the tool that has alert records linked directly to the search functionality of the Enterprise Log Search and Archive (ELSA)?
The Enterprise Log Search and Archive (ELSA) is an enterprise-level tool for allowing searching and archiving of NSM data. Searches can be executed by pivoting from Sguil to ELSA as its search functionality is directly linked to Sguil alert records.
What are the three core functions provided by the Security Onion? (Choose three.)
- threat containment
- security device management
- full packet capture
- intrusion detection
- alert analysis
- business continuity planning
Security Onion is an open source suite of Network Security Monitoring (NSM) tools for evaluating cybersecurity alerts. For cybersecurity analysts the Security Onion provides full packet capture, network-based and host-based intrusion detection systems, and alert analysis tools.
Refer to the exhibit. A network security specialist issues the command tcpdump to capture events. What is the function provided by the ampersand symbol used in the command?
- It tells the Linux shell to display the captured data on the console.
- It tells the Linux shell to execute the tcpdump process indefinitely.
- It instructs the tcpdump to capture data that starts with the symbol.
- It tells the Linux shell to execute the tcpdump process in the background.
The ampersand symbol tells the Linux shell to execute tcpdump in the background.
A law office uses a Linux host as the firewall device for the network. The IT administrator is adding a rule to the firewall iptables to block internal hosts from connecting to a remote device that has the IP address 184.108.40.206. Which command should the administrator use?
- iptables -I PASS -p tcp -d 220.127.116.11 –dport 7777 -j DROP
- iptables -I INPUT -p tcp -d 18.104.22.168 –dport 7777 -j DROP
- iptables -I OUTPUT -p tcp -d 22.214.171.124 –dport 7777 -j DROP
- iptables -I FORWARD -p tcp -d 126.96.36.199 –dport 7777 -j DROP
The firewall iptables uses the concepts of chains and rules to filter traffic:
INPUT chain – handles traffic entering the firewall and destined to the firewall device itself
FORWARD chain – handles traffic originated somewhere else and passing through the firewall device
A threat actor has successfully breached the network firewall without being detected by the IDS system. What condition describes the lack of alert?
- false negative
- false positive
- true positive
- true negative
A false negative is where no alert exists and exploits are not being detected by the security systems that are in place.
What procedure should be avoided in a digital forensics investigation?
- Secure physical access to the computer under investigation.
- Make a copy of the hard drive.
- Recover deleted files.
- Reboot the affected system upon arrival.
Digital forensic investigation is the science of collecting and examining electronic evidence that can evaluate damage to a computer as a result of an electronic attack or that can recover lost information from a system in order to prosecute a criminal. To prevent tampering and alteration of the suspect data, a data forensic analysis should be conducted on a copy of the suspect computer. Furthermore, restarting a computer may change or overwrite files and inadvertently destroy evidence.
Which tool would an analyst use to start a workflow investigation?
Sguil is a GUI-based application used by security analysts to analyze network security events.
Which two types of unreadable network traffic could be eliminated from data collected by NSM? (Choose two.)
- SSL traffic
- STP traffic
- IPsec traffic
- broadcast traffic
- routing updates traffic
To reduce the huge amount of data collected so that cybersecurity analysts can focus on critical threats, some less important or unusable data could be eliminated from the datasets. For example, encrypted data, such as IPsec and SSL traffic, could be eliminated because it is unreadable in a reasonable time frame.
Which term is used to describe the process of converting log entries into a common format?
For processing log entries, data normalization can organize and convert data values in datasets from difference sources into common format. The normalization makes it easy for further data analysis and reporting.
Which statement describes a feature of timestamps in Linux?
- All devices generate human readable and Unix Epoch timestamps.
- Human readable timestamps measure the number of seconds that have passed since January 1, 1970.
- It is easier to work with Unix Epoch timestamps for addition and subtraction operations.
- Unix Epoch timestamps are easier for humans to interpret.
Which two strings will be matched by the regular expression? (Choose two.)
Regular expressions allow forensics analysts to search through large quantities of text information for patterns of data. Some common operators used in regular expressions are as follows:
$ End of a line.
 Any single value within the square brackets.
* Preceding sub-expression zero or more times.
[^1] Any character except those bound by the [^ and the].
Refer to the exhibit. A cybersecurity analyst is using Sguil to verify security alerts. How is the current view sorted?
- by frequency
- by source IP
- by date/time
- by sensor number
The CNT column, between the ST and Sensor columns, displays the frequency of alerts. By sorting with frequency, the analyst will get a better sense of what has happened on the network.
How is the hash value of files useful in network security investigations?
- It is used to decode files.
- It verifies confidentiality of files.
- It is used as a key for encryption.
- It helps identify malware signatures.
When ELSA is used to investigate downloaded files, the hash value of each file is created and stored with other information about the file. If a cybersecurity analyst is suspicious of the file, the hash value can be submitted to an online malware repository site to determine if the file is known malware.
How does an application program interact with the operating system?
- sending files
- using processes
- making API calls
- accessing BIOS or UEFI
Application programs interact with an operating system through system calls to the OS application programming interface (API). These system calls allow access to many aspects of system operation such as software process control, file management, device management, and network access.
Which three procedures in Sguil are provided to security analysts to address alerts? (Choose three.)
- Expire false positives.
- Categorize true positives.
- Escalate an uncertain alert.
- Construct queries using Query Builder.
- Pivot to other information sources and tools.
- Correlate similar alerts into a single line.
Sguil is a tool for addressing alerts. Three tasks can be completed in Sguil to manage alerts:
Alerts that have been found to be false positives can be expired.
An alert can be escalated if the cybersecurity analyst is uncertain how to handle it.
Events that have been identified as true positives can be categorized.
Refer to the exhibit. A network security analyst is examining captured data using Wireshark. The captured frames indicate that a host is downloading malware from a server. Which source port is used by the host to request the download?
During the TCP three-way handshake process, the output shows that the host uses source port 48598 to initiate the connection and request the download.
Refer to the exhibit. A network security analyst is using the Follow TCP Stream feature in Wireshark to rebuild the TCP transaction. However, the transaction data seems indecipherable. What is the explanation for this?
- The data shown is line noise.
- The transaction data is corrupted.
- The transaction data is a binary file.
- The transaction data is encoded with Base64.
The host is downloading W32.Nimda.Amm.exe, a binary file. Wireshark does not know how to represent it. The displayed symbols are the best guess at making sense of the binary data while decoding it as text.
Which tool is developed by Cisco and provides an interactive dashboard that allows investigation of the threat landscape?
Cisco Talos provides an interactive dashboard that allows investigation of the threat landscape.
Which type of evidence supports an assertion based on previously obtained evidence?
- best evidence
- corroborating evidence
- direct evidence
- indirect evidence
Corroborating evidence is evidence that supports a proposition already supported by initial evidence, therefore confirming the original proposition. Circumstantial evidence is evidence other than first-hand accounts of events provided by witnesses.
According to NIST, which step in the digital forensics process involves extracting relevant information from data?
NIST describes the digital forensics process as involving the following four steps:
Match the characteristic to the method of security analysis.
Match the field in the Event table of Sguil to the description.
Place the evidence collection priority from most volatile to least volatile as defined by the IETF guidelines.
Use the following scenario to answer the questions. A company has just had a cybersecurity incident. The threat actor or actors appeared to have a goal of network disruption and appeared to use a common security hack tool that overwhelmed a particular server with a large amount of traffic, which rendered the server inoperable.
How would a certified cybersecurity analyst classify this type of threat actor?
Amateur or script kiddies use common existing tools found on the internet to launch attacks. Hacktivists disrupt services in protest against organizations or governments for a particular political or social idea. State-sponsored threat actors use cyberspace for industrial espionage or interfering with another country in some way. Terrorist groups attack for a specific cause.
The security team at this company has removed the compromised server and preserved it with the security hack still embedded. What type of evidence is this?
Evidence is classified as direct or indirect. Direct evidence is that the accused was caught in the act, there is an eyewitness, or the evidence is indisputable. Three other types of evidence are best, corroborating, and indirect. Best is evidence in its original state. Corroborating evidence supports an assertion developed from best evidence. Indirect evidence provides support for a hypothesis.
Which type of attack was achieved?
- social engineering
A denial-of-service attack results in an interruption of service to users, devices, or applications or all three. A direct DoS attack uses zombies and bots in order to have a coordinated attack from a multitude of sources. An access attack exploit known vulnerabilities in servers. Social engineering is a specific type of access attack toward an individual in an effort to get that individual to divulge information.
What would be the threat attribution in this case?
- evaluating the server alert data
- obtaining the most volatile evidence
- determining who is responsible for the attack
- reporting the incident to the proper authorities
Threat attribution refers to determining the individual, organization, or nation responsible for a successful intrusion or attack incident. The security investigation team correlates all the evidence in order to identify commonalities between tactics, techniques, and procedures (TPPs) for known and unknown threat actors.
What are three common tools used to carry out this type of attack? (Choose three.)
- ping sweep
- TCP SYN flood
- buffer overflow
- IP, MAC, and DHCP spoofing
- smurf attack
Three tools used to carry out this type of attack are TCP SYN flood, buffer overflow, and smurf attack. All three attacks send data in order to overwhelm another network device. A ping sweep is used in reconnaissance. Man-in-the middle occurs when the threat actor collects data in order to read, modify, or redirect that data. IP, MAC, and DHCP spoofing attacks are used to falsify address data.