Searching raw logs using Raw Log Scan

When you execute a search, Chronicle first examines the security data that has been ingested, parsed, and normalized. If the information you are searching for is not found in the normalized data, you can use Raw Log Scan to examine the raw unparsed logs. You can also use regular expressions to more closely examine the raw logs.

You can use Raw Log Scan to investigate artifacts that appear in logs but are not indexed, including:

  • Usernames
  • Filenames
  • Registry keys
  • Command-line arguments
  • Raw HTTP request-related data
  • Domain names based on regular expressions
  • Asset names and addresses

For information on how to use raw log scan and regular expressions, see the following sections.

Raw log scan

To use Raw Log Scan, enter a search string in the search field on either the landing page or the menu bar (for example, an MD5 hash). Enter at least 4 characters (including wildcards). If Chronicle cannot find the search string, it opens the Raw Logs Scan option. Specify the Start Time and End Time (the default is 1 week) and click SEARCH.

Raw Log Scan from the Landing Page Raw Log Scan from the landing page

Events associated with the search string are displayed. You can open the associated raw log by clicking the arrow button.

You can also click the Log Sources drop-down menu and select one or more of the data sources you are sending to Chronicle to search. The default setting is All.

Regular expressions

You can use regular expressions to search for and match sets of character strings within your security data using Chronicle. Regular expressions enable you to narrow your search down using fragments of information, as opposed to using (for example) a complete domain name.

To run a search using regular expression syntax, enter your search in the Search field with the regular expression, check the Run Query as Regex checkbox, and click SEARCH. Your regular expression must be from 4 to 66 characters long.

Raw Log Scan Run as a Regular Expression Raw Log Scan run as a regular expression

The Chronicle's regular expression infrastructure is based on Google RE2, an open-source regular expression engine. Chronicle uses the same regular expression syntax. See the RE2 documention for more information.

The following table highlights some of the common regular expression syntaxes you can use for your searches.

Any character .
x number of any characters {x}
Character class [xyz]
Negated character class [^xyz]
Alphanumeric (0-9A-Za-z) [[:alnum:]]
Alphabetic (A-Za-z) [[:alpha:]]
Digits (0-9) [[:digit:]]
Lower case (a-z) [[:lower:]]
Upper case (A-Z) [[:upper:]]
Word characters (0-9A-Za-z_) [[:word:]]
Hex digit (0-9A-Fa-f) [[:xdigit:]]

The following examples illustrate how you could use this syntax to search across your data:

  • goo.le\.com—match google.com, goooogle.com, etc.
  • goo\w{3}\.com—match google.com, goodle.com, goojle.com, etc.
  • [[:digit:]]\.[[:alpha:]]—match 34323.system, 23458.office, 897.net, etc.

Sample regular expressions to search for Windows logs

This section provides regular expression query strings you can use with Chronicle raw log scan to find commonly monitored Windows events. These examples assume the Windows log messages are in JSON format.

For more information about commonly monitored Windows Event IDs, see the Events to Monitor topic in Microsoft documentation. The examples provided follow a similar pattern, described in these use cases.

Use Case: Return events with the EventID 1150
Regex String: \"EventID\"\:\s*1150
Values Matched: "EventID":1150
Use Case:Return events with an Event ID that is either 1150 or 1151
Regex String (?:\"EventID\"\:\s*)(?:1150|1151)
Values Matched "EventID":1150 and "EventID":1151
Use Case: Return events with an Event ID that is either 1150 or 1151, and with ThreatID 9092
Regex String (?:\"EventID\"\:\s*)(?:1150|1151).*(?:\"ThreadID\"\:\s*9092)
Values Matched "EventID":1150 <...any number of characters...> "ThreadID":9092
and
"EventID":1151 <...any number of characters...glt; "ThreadID":9092

Find account management events

These regular expression query strings identify common account management events using the EventID attribute.

Type of Event Regular Expression
User Account Created EventID\"\:\s*4720
User Account Enabled EventID\"\:\s*4722
User Account Disabled EventID\"\:\s*4725
User Account Deleted EventID\"\:\s*4726
User Rights Modification EventID\"\:\s*4703
Member Added to Security Enabled Global Group EventID\"\:\s*4728
Member Removed from Security Enabled Global Group EventID\"\:\s*4729
Security Enabled Global Group was Deleted EventID\"\:\s*4730

Find logon success events

These regular expression query strings identify types of successful logon events using the EventID and LogonType attributes.

Type of Event Regular Expression
Logon Success EventID\"\:\s*4624
Logon Success - Interactive (LogonType=2) EventID\"\:\s*4624.*?LogonType\"\:\s*\"2\"
Logon Success - Batch Login (LogonType=4) EventID\"\:\s*4624.*?LogonType\"\:\s*\"4\"
Logon Success - Service Login (LogonType=5) EventID\"\:\s*4624.*?LogonType\"\:\s*\"5\"
Logon Success - RemoteInteractive Login (LogonType=10) EventID\"\:\s*4624.*?LogonType\"\:\s*\"10\"
Logon Success - Interactive, Batch, Service, or RemoteInteractive (?:EventID\"\:\s*4624.*?LogonType\"\:\s*\")(?:2|4|5|10)\"

Find logon failure events

These regular expression query strings identify types of failed logon events using the EventID and LogonType attributes.

Type of Event Regular Expression
Logon Failure EventID\"\:\s*4625
Logon Failure - Interactive (LogonType=2) EventID\"\:\s*4625.*?LogonType\"\:\s*\"2\"
Logon Failure - Batch Login (LogonType=4) EventID\"\:\s*4625.*?LogonType\"\:\s*\"4\"
Logon Failure - Service Login (LogonType=5) EventID\"\:\s*4625.*?LogonType\"\:\s*\"5\"
Logon Failure - RemoteInteractive Login (LogonType=10) EventID\"\:\s*4625.*?LogonType\"\:\s*\"10\"
Logon Failure - Interactive, Batch, Service, or RemoteInteractive (?:EventID\"\:\s*4625.*LogonType\"\:\s*\")(?:2|4|5|10)\"

Find process, service and task events

These regular expression query strings identify certain process and service events using the EventID attribute.

Type of Event Regular Expression
Process Start EventID\"\:\s*4688
Process Exit EventID\"\:\s*4689
Service Installed EventID\"\:\s*4697
New Service Created EventID\"\:\s*7045
Schedule Task Created EventID\"\:\s*4698

These regular expression query strings identify different types of process and service related events using the EventID attribute.

Type of Event Regular Expression
Audit Log Cleared EventID\"\:\s*1102
Object Access Attempted EventID\"\:\s*4663
Share Accessed EventID\"\:\s*5140