Merge branch 'master' into devel-sigmac

README.md

@@ -7,25 +7,60 @@ Generic Signature Format for SIEM Systems
 
 Sigma is a generic and open signature format that allows you to describe relevant log events in a straight forward manner. The rule format is very flexible, easy to write and applicable to any type of log file. The main purpose of this project is to provide a structured form in which researchers or analysts can describe their once developed detection methods and make them shareable with others.
 
-![sigma_description](./images/Sigma-description.png)
+Sigma is for log files what [Snort](https://www.snort.org/) is for network traffic and [YARA](https://github.com/VirusTotal/yara) is for files.   
 
 This repository contains:
 
 * Sigma rule specification in the [Wiki](https://github.com/Neo23x0/sigma/wiki/Specification)
 * Open repository for sigma signatures in the ```./rules```subfolder
-* A converter that generate searches/queries for different SIEM systems [in development]
+* A converter that generate searches/queries for different SIEM systems [work in progress]
 
-# Converter
+# Use Cases
 
-The converter is written in Python 3 and requires PyYAML. Invoke it with `--help` for usage instructions.
+* Describe your once discovered detection method in Sigma to make it sharable 
+* Share the signature in the appendix of your analysis along with file hashes and C2 servers
+* Share the signature in threat intel communities - e.g. via MISP
+* Provide Sigma signatures for malicious behaviour in your application (Error messages, access violations, manipulations) 
+* Integrate a new log into your SIEM and check the Sigma repository for available rules
+* Develop an experimental detection method, write a Sigma rule, share it and ask for feedback
+* Write a rule converter for your custom log analysis tool and process new Sigma rules automatically
+* Provide a free or commercial feed for Sigma signatures
 
-# Slides
+# Sigma Converter
+
+The converter is currently under development in the *devel-sigmac* branch of this project. It has currently the
+following capabilities:
+
+* Parsing of Sigma rule files
+* Conversion of searches into Elasticsearch and Splunk queries
+
+Planned main features are:
+
+* Conversion of aggregation expressions (after the pipe character)
+* Output of Kibana JSON configurations
+
+Support for further SIEM solutions can be added by developing an corresponsing output backend class.
+
+![sigma_description](./images/Sigma-description.png)
+
+# Why Sigma
+
+Today, everyone collects log data for analysis. People start working on their own, processing numerous white papers, blog posts and log analysis guidelines, extracting the necessary information and build their own searches and dashboard. Some of their searches and correlations are great and very useful but they lack a standardized format in which they can share their work with others. 
+
+Others provide excellent analyses for threat groups, sharing file indicators, C2 servers and YARA rules to detect the malicious files, but describe a certain malicious service install or remote thread injection in a separate paragraph. Security analysts, who read that paragraph then extract the necessary information and create rules in their SIEM system. The detection method never finds a way into a repository that is shared, structured and archived. 
+
+The lower layers of the OSI layer are well known and described. Every SIEM vendor has rules to detect port scans, ping sweeps and threats like the ['smurf attack'](https://en.wikipedia.org/wiki/Smurf_attack). But the higher layers contain numerous applications and protocols  with special characteristics that write their own custom log files. SIEM vendors consider the signatures and correlations as their intelectual property and do not tend to share details on the coverage. 
+
+Sigma is meant to be an open standard in which detection mechanisms can be defined, shared and collected in order to improve the detection capabilities on the application layers for everyone. 
+
+![sigma_why](./images/Problem_OSI_v01.png)
+
+## Slides
 
 See the first slide deck that I prepared for a private conference in mid January 2017.
 
 [Sigma - Make Security Monitoring Great Again](https://www.slideshare.net/secret/gvgxeXoKblXRcA)
 
-
 # Specification
 
 The specifications can be found in the [Wiki](https://github.com/Neo23x0/sigma/wiki/Specification). 
@@ -56,3 +91,9 @@ Windows 'Security' Eventlog: Suspicious Number of Failed Logons from a Single So
 * Integration of feedback into the rule specifications
 * Collecting rule input from fellow researchers and analysts
 * Attempts to convince others to use the rule format in their reports, threat feeds, blog posts, threat sharing platforms
+
+# Credits
+
+This is a private project mainly developed by Florian Roth and Thomas Patzke with feedback from many fellow analysts and friends.  
+
+Copyright for Tree Image: [studiobarcelona / 123RF Stock Photo](http://www.123rf.com/profile_studiobarcelona)

rules/network/net_susp_network_scan.yml

@@ -1,5 +1,8 @@
 title: Network Scans
 description: Detects many failed connection attempts to different ports or hosts
+author: Thomas Patzke
+logsource:
+    type: firewall
 detection:
     selection:
         log: network

rules/web/web_multiple_suspicious_resp_codes_single_source.yml

@@ -1,10 +1,10 @@
 title: Multiple suspicious Response Codes caused by Single Client
 description: Detects possible exploitation activity or bugs in a web application
+author: Thomas Patzke
+logsource:
+    type: webserver
 detection:
     selection:
-        log: 
-          - access.log
-          - error.log
         response:
           - 400
           - 401

rules/web/web_webshell_keyword.yml

@@ -1,10 +1,9 @@
 title: Webshell Detection by Keyword
-description: Detects webshells that use GET requests by keyword sarches in URL strings 
+description: Detects webshells that use GET requests by keyword sarches in URL strings
+author: Florian Roth
+logsource:
+    type: webserver
 detection:
-    selection:
-        log: 
-          - access.log
-          - error.log
     keywords:
         - '=whoami'
         - '=net%20user'

rules/windows/builtin/win_alert_mimikatz_keywords.yml

@@ -1,5 +1,8 @@
 title: Mimikatz Usage
 description: This method detects mimikatz keywords in different Eventlogs (some of them only appear in older Mimikatz version that are however still used by different threat groups)
+author: Florian Roth
+logsource:
+    product: windows
 detection:
     selection:
         EventLog:

rules/windows/builtin/win_av_relevant_match.yml

@@ -1,5 +1,8 @@
 title: Relevant Anti-Virus Event
 description: This detection method points out highly relevant Antivirus events
+author: Florian Roth
+logsource:
+    product: windows
 detection:
     selection:
         EventLog: Application

rules/windows/builtin/win_susp_eventlog_cleared.yml

@@ -1,13 +1,15 @@
 title: Eventlog Cleared
-description: Some threat groups tend to delete the local 'Security' Eventlog using certain utitlities
+description: One of the Windows Eventlogs has been cleared
+reference: https://twitter.com/deviouspolack/status/832535435960209408
+author: Florian Roth
+logsource:
+    product: windows
 detection:
     selection:
-        EventLog: Security
-        EventID:
-            - 517
-            - 1102
+        EventLog: System
+        EventID: 104
     condition: selection
 falsepositives:
-    - Rollout of log collection agents (the setup routine often includes a reset of the local Eventlog)
-    - System provisioning (system reset before the golden image creation)
-level: high
+    - Unknown
+level: medium
+

rules/windows/builtin/win_susp_failed_logon_reasons.yml

@@ -1,6 +1,8 @@
 title: Account Tampering - Suspicious Failed Logon Reasons
 description: This method uses uncommon error codes on failed logons to determine suspicious activity and tampering with accounts that have been disabled or somehow restricted.
+author: Florian Roth
 logsource:
+    product: windows
 detection:
     selection:
         EventLog: Security

rules/windows/builtin/win_susp_failed_logons_single_source.yml

@@ -1,5 +1,8 @@
 title: Multiple Failed Logins with Different Accounts from Single Source System
 description: Detects suspicious failed logins with different user accounts from a single source system 
+author: Florian Roth
+logsource:
+    product: windows
 detection:
     selection:
         EventLog: Security
@@ -17,3 +20,5 @@ falsepositives:
     - Other multiuser systems like Citrix server farms
     - Workstations with frequently changing users 
 level: medium
+
+

rules/windows/builtin/win_susp_kerberos_manipulation.yml

@@ -1,5 +1,8 @@
 title: Kerberos Manipulation
 description: This method triggers on rare Kerberos Failure Codes caused by manipulations of Kerberos messages
+author: Florian Roth
+logsource:
+    product: windows
 detection:
     selection:
         EventLog: Security

rules/windows/builtin/win_susp_lsass_dump.yml

@@ -2,6 +2,8 @@ title: Password Dumper Activity on LSASS
 description: Detects process handle on LSASS process with certain access mask and object type SAM_DOMAIN 
 status: experimental
 reference: https://twitter.com/jackcr/status/807385668833968128
+logsource:
+    product: windows
 detection:
     selection:
         EventLog: Security
@@ -13,3 +15,4 @@ detection:
 falsepositives:
     - Unkown
 level: high
+

rules/windows/builtin/win_susp_rc4_kerberos.yml

@@ -1,7 +1,9 @@
 title: Suspicious Kerberos RC4 Ticket Encryption
 status: experimental
 reference: https://adsecurity.org/?p=3458
-description: Detects logons using RC4 encryption type 
+description: Detects logons using RC4 encryption type
+logsource:
+    product: windows
 detection:
     selection:
         EventLog: Security

rules/windows/builtin/win_susp_security_eventlog_cleared.yml

@@ -0,0 +1,16 @@
+title: Security Eventlog Cleared
+description: Some threat groups tend to delete the local 'Security' Eventlog using certain utitlities
+author: Florian Roth
+logsource:
+    product: windows
+detection:
+    selection:
+        EventLog: Security
+        EventID:
+            - 517
+            - 1102
+    condition: selection
+falsepositives:
+    - Rollout of log collection agents (the setup routine often includes a reset of the local Eventlog)
+    - System provisioning (system reset before the golden image creation)
+level: high

rules/windows/sysmon/sysmon_mimikatz_detection_lsass.yml

@@ -2,6 +2,8 @@ title: Mimikatz Detection LSASS Access
 status: experimental
 description: Detects process access to LSASS which is typical for Mimikatz (0x1000 PROCESS_QUERY_ LIMITED_INFORMATION, 0x0400 PROCESS_QUERY_ INFORMATION, 0x0010 PROCESS_VM_READ)
 reference: https://onedrive.live.com/view.aspx?resid=D026B4699190F1E6!2843&ithint=file%2cpptx&app=PowerPoint&authkey=!AMvCRTKB_V1J5ow
+logsource:
+    product: sysmon
 detection:
     selection:
         - EventLog: Microsoft-Windows-Sysmon/Operational

rules/windows/sysmon/sysmon_mimikatz_inmemory_detection.yml

@@ -2,6 +2,8 @@ title: Mimikatz In-Memory Detection
 status: experimental
 description: Detects certain DLL loads when Mimikatz gets executed
 reference: https://securityriskadvisors.com/blog/post/detecting-in-memory-mimikatz/
+logsource:
+    product: sysmon
 detection:
     dllload1:
         EventLog: Microsoft-Windows-Sysmon/Operational

rules/windows/sysmon/sysmon_password_dumper_lsass.yml

@@ -1,6 +1,8 @@
 title: Password Dumper Remote Thread in LSASS 
 description: Detects password dumper activity by monitoring remote thread creation EventID 8 in combination with the lsass.exe process as TargetImage. The process in field Process is the malicious program. A single execution can lead to hundrets of events.
-reference: Internal research
+author: Thomas Patzke
+logsource:
+    product: sysmon
 detection:
     selection:
         EventLog: Microsoft-Windows-Sysmon/Operational

rules/windows/sysmon/sysmon_susp_driver_load.yml

@@ -1,5 +1,8 @@
 title: Suspicious Driver Load from Temp
 description: Detetcs a driver load from a temporary directory
+author: Florian Roth
+logsource:
+    product: sysmon
 detection:
     selection:
         EventLog: Microsoft-Windows-Sysmon/Operational

rules/windows/sysmon/sysmon_susp_mmc_source.yml

@@ -2,6 +2,8 @@ title: Proceses created by MMC
 status: experimental
 description: Processes started by MMC could by a sign of lateral movement using MMC application COM object 
 reference: https://enigma0x3.net/2017/01/05/lateral-movement-using-the-mmc20-application-com-object/
+logsource:
+    product: sysmon
 detection:
     selection:
         EventLog: Microsoft-Windows-Sysmon/Operational
@@ -13,4 +15,4 @@ detection:
     condition: selection and not exclusion
 falsepositives:
     - unknown
-level: high
+level: medium

rules/windows/sysmon/sysmon_vul_java_remote_debugging.yml

@@ -1,5 +1,8 @@
 title: Java running with Remote Debugging
 description: Detcts a JAVA process running with remote debugging allowing more than just localhost to connect
+author: Florian Roth
+logsource:
+    product: sysmon
 detection:
     selection:
         EventLog: Microsoft-Windows-Sysmon/Operational

rules/windows/sysmon/sysmon_webshell_detection.yml

@@ -1,5 +1,8 @@
 title: Webshell Detection With Command Line Keywords 
-description: Detects certain command line parameters often used during reconnissaince activity via web shells  
+description: Detects certain command line parameters often used during reconnissaince activity via web shells
+author: Florian Roth
+logsource:
+    product: sysmon
 detection:
     selection:
         EventLog: Microsoft-Windows-Sysmon/Operational

rules/windows/sysmon/sysmon_webshell_spawn.yml

@@ -1,6 +1,9 @@
 title: Shells spawned by Web Servers
 status: experimental
 description: Web servers that spawn shell processes could be the result of a successfully placed web shell or an other attack
+author: Thomas Patzke
+logsource:
+    product: sysmon
 detection:
     selection:
         EventLog: Microsoft-Windows-Sysmon/Operational