CCFR-201 CrowdStrike Certified Falcon Responder Questions and Answers

According to the CrowdStrike Falcon® Data Replicator (FDR) Add-on for Splunk Guide, when you release a file from quarantine, you are restoring it to its original location and allowing it to execute on any host in your organization2. This action also removes the file from the quarantine list and deletes it from the CrowdStrike Cloud2.

According to the [CrowdStrike Falcon® Data Replicator (FDR) Add-on for Splunk Guide], Sensor Visibility Exclusions allow you to exclude files or directories from being monitored by the sensor. This can reduce the amount of data sent to the CrowdStrike Cloud and improve performance. Sensor Visibility Exclusion patterns are written in Glob Syntax, which is a simple pattern matching syntax that supports wildcards, such as *, ?, and . For example, you can use *.exe to exclude all files with .exe extension.

According to the CrowdStrike Falcon® Data Replicator (FDR) Add-on for Splunk Guide, the allowlist feature allows you to exclude files or directories from being scanned or blocked by CrowdStrike’s machine learning engine or indicators of attack (IOAs)2. This can reduce false positives and improve performance2. When you allowlist a hash, you are allowing that file to execute on any host that belongs to your organization’s CID (customer ID)2. This does not affect other Falcon customers or hosts outside your CID2.

According to the CrowdStrike Falcon Devices Add-on for Splunk Installation and Configuration Guide v3.1.5+, the Process Timeline search returns all cloudable events associated with a given process, such as process creation, network connections, file writes, registry modifications, etc1. This allows you to see a comprehensive view of what a process was doing on a host1.

According to the CrowdStrike Falcon® Data Replicator (FDR) Add-on for Splunk Guide, IOC Management allows you to manage indicators of compromise (IOCs), which are artifacts such as hashes, IP addresses, or domains that are associated with malicious activities2. You can set different actions for IOCs, such as Allow, No Action, or Always Block2. When you set a hash to Always Block through IOC Management, you are preventing that file from executing on any host in your organization by default2. This action also generates a detection alert when the file is blocked2.

According to the CrowdStrike Falcon Devices Add-on for Splunk Installation and Configuration Guide v3.1.5+, the IP Search tool allows you to search for an IP address and view a summary of information from Falcon events that contain that IP address1. The summary includes the hostname, sensor ID, OS, country, city, ISP, ASN, geolocation, process name, command line, and organizational unit of the host that communicated with that IP address1. This is an advantage of using the IP Search tool because it provides host, process, and organizational unit data without the need to write a query1.

According to the CrowdStrike Falcon® Data Replicator (FDR) Add-on for Splunk Guide, IOA exclusions allow you to exclude files or directories from being detected or blocked by CrowdStrike’s indicators of attack (IOAs), which are behavioral rules that identify malicious activities1. This can reduce false positives and improve performance1. When you configure and apply an IOA exclusion, the impact is that the associated detection will be suppressed and theassociated process would have been allowed to run1. This means that you will not see any alerts or events related to that IOA in the console1.

According to the CrowdStrike Falcon Devices Add-on for Splunk Installation and Configuration Guide v3.1.5+, Global Prevalence and Local Prevalence are two fields that provide information about how common or rare a file is based on its hash value2. Global Prevalence tells you how frequently the hash of the triggering file is seen across all CrowdStrike customer environments2. Local Prevalence tells you how frequently the hash of the triggering file is seen within your environment (CID)2. These fields can help you assess the risk and impact of a detection2.

According to the CrowdStrike Falcon Devices Add-on for Splunk Installation and Configuration Guide v3.1.5+, pivoting to an Event Search from a detection takes you to the raw Insight event data and provides you with a number of Event Actions1. Insight events are low-level events that are generated by the sensor for various activities, such as process executions, file writes, registry modifications, network connections, etc1. You can view these events in a table format and use various filters and fields to narrow down the results1. You can also select one or more events and perform various actions, such as show a process timeline, show a host timeline, show associated event data, show a +/- 10-minute window of events, etc1. These actions can help you investigate and analyze events more efficiently and effectively1.

According to the CrowdStrike Falcon Devices Add-on for Splunk Installation and Configuration Guide v3.1.5+, the Hash Search tool allows you to search for one or more SHA256 hashes and view a summary of information from Falcon events that contain those hashes1. The summary includes the hostname, sensor ID, OS, country, city, ISP, ASN, geolocation, process name, command line, and organizational unit of the host that loaded or executed those hashes1. You can also see a count of detections and incidents related to those hashes1. Under Process Executions, you can see the process name and command line for each hash execution1.

According to the [CrowdStrike website], the Discover page is where you can search for and analyze various types of indicators of compromise (IOCs), such as hashes, IP addresses, or domains that are associated with malicious activities. You can use various tools, such as Hash Executions, IP Addresses, Remote or Network Logon Activity, etc., to perform different types of searches and view the results in different ways. If you want to search for any activity related to an IP address that was compromised by a third-party vendor, you can use the IP Addresses tool to do so. You can input the IP address and see a summary of information from Falcon events that contain that IP address, such as hostname, sensor ID, OS, country, city, ISP, ASN, geolocation, process name, command line, and organizational unit of the host that communicated with that IP address.

According to the CrowdStrike Falcon Devices Add-on for Splunk Installation and Configuration Guide v3.1.5+, there are three ways to export process event data from a detection in .CSV format1:

• You can use the Process Timeline tool and click on “Export CSV” button at the top right corner1.
• You can use the Event Search tool and select one or more events and click on “Export CSV” button at the top right corner1.
• You can use the Full Detection Details tool and choose the “View Process Activity” option from any process node in the process tree view1. This will show you all events generated bythat process in a rows-and-columns style view1. You can then click on “Export CSV” button at the top right corner1.

According to the [CrowdStrike Falcon Devices Add-on for Splunk Installation and Configuration Guide v3.1.5+], event types are categories of events that are generated by the sensor for various activities, such as process executions, file writes, registry modifications, network connections, etc. There are many valid event types, such as StartOfProcess, ProcessRollup2, DnsRequest, etc. However, EndOfProcess is not a valid event type, as there is no such event that records the end of a process.

According to the CrowdStrike Falcon Devices Add-on for Splunk Installation and Configuration Guide v3.1.5+, Reduced Functionality Mode (RFM) is a state where a host’s sensor has limited functionality due to various reasons, such as license expiration, network issues, tampering attempts, etc1. You can find hosts that are in RFM by using the Host Search tool and filtering by Sensor Status = RFM1. You can also view details about why a host is in RFM by clicking on its hostname1.

According to the CrowdStrike Falcon® Data Replicator (FDR) Add-on for Splunk Guide, the Always Block action allows you to block a file from executing on any host in your organization based on its hash value2. This action can be used to prevent known malicious files from running on your endpoints2.