Blackhat USA 2016 - What's the DFIRence for ICS?
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The document provides an overview of digital forensics and incident response (DFIR) for industrial control systems (ICS), detailing tools, techniques, and processes for collecting and analyzing data from embedded devices like RTUs. It emphasizes the importance of evidence collection, anomaly detection, and the unique challenges presented by ICS, including the lack of specific DFIR tools. Additionally, it discusses manual data collection methods and the use of various software for effective incident response in ICS environments.
![Example of live memory code injection & mem dump on the D20MX
• Inject code via VxWorks C shell memory edit command m to simulate a rootkit
[SCREENSHOTS OR VIDEO RECORDING HERE]
• Collect volatile memory using the dump memory command d
[SCREENSHOTS OR VIDEO RECORDING HERE]
23](https://image.slidesharecdn.com/us-16-sistrunk-triplett-whats-the-dfirence-for-ics-160804171101/85/Blackhat-USA-2016-What-s-the-DFIRence-for-ICS-23-320.jpg)
Blackhat USA 2016 - What's the DFIRence for ICS?
- 1. What’s the DFIRence for ICS? Chris Sistrunk, PE Senior Consultant, FireEye @chrissistrunk Josh Triplett Senior Reverse Engineer, FireEye 1
- 2. Agenda • Digital Forensics and Incident Response Overview • DFIR for ICS • What’s the DFIRence? • Embedded Devices • What to Collect • What to Analyze • RTU Examples • GE D20MX • VxWorks DFIR Tool • SEL-3530 RTAC 2
- 3. Incident Response Overview “Find Evil” • Assess the situation • Define objectives • Collect evidence • Perform analysis • Communicate • Develop remediation plan • Document findings http://www.cumbriafire.gov.uk/about/photo/engines/incident-response.asp 3
- 4. Digital Forensics Overview • Data Collection • Data Files • OS (volatile and non-volatile) • Network Traffic • Applications • Examination • Analysis • Reporting NIST SP 800-86 4
- 5. Traditional DFIR tools Mature • Tools • Redline • Volatility • Websites • Cheatsheets • Books 5
- 6. What’s the DFIRence for ICS? 6
- 7. ICS anomaly incident? • An anomaly of some kind has occurred • Increased network activity, strange behavior, failure • Now we need to investigate the anomaly • Is it known bad? • Is it unknown bad? • Do we escalate this to a security incident? • Who do we call? • Engineers, Admins, PR, Safety • Vendors 7
- 8. Don’t! 8
- 9. ICS forensics collection tools • No ICS-specific DFIR tools…especially embedded devices • But, we can collect data manually using other tools 9
- 10. Embedded devices: What to collect? Physical data • Exact location of device • Device description • Identifying info (manufacturer, S/N, P/N, name) • Connections (serial, ethernet, USB) • Front/back panel LED status • Power consumption • Temperature (if running hot) • Evidence of tampering Digital data • Running configuration (including user accounts) • Last-known good configuration • Running firmware, approved firmware • CPU usage %, Memory usage % (RAM, Storage) • Running processes • Active ports (serial, ethernet, USB, etc) • Logs (security, events) • Memory dump (if possible) 10
- 11. Embedded devices: What to analyze? Find Evil…or ways for evil to do evil First Responders: ICS Engineer or Technician, Network Engineer, Vendor • What do the user and event logs reveal? (these need to be viewed first as they may rollover) • Does the configuration match the firmware? Is the firmware approved from FAT/SAT? • Running config / last known good config / standard config • Is the configuration and logic correct for the process? • Are communications (serial, ethernet, USB, wireless) normal as compared with known good? Vendor, Digital Forensics Specialist, Embedded Systems Analyst • Analyze embedded OS files, captured data at rest, captured data in transit • Volatile memory if possible (to look for code injection and potential rootkits) Fast Slower Time 11
- 12. Let’s do DFIR on two substation RTUs 12
- 13. Time to…RTFM 13
- 14. Data Collection: D20MX Specs • 667 MHz embedded PowerQUICC II Pro • 1024 MB of 266 MHz DDR2 RAM with ECC • 16 MB NVRAM for persistent event storage • 8 MB boot flash, 256 MB firmware flash • VxWorks RTOS Tools to use • D20MX Product Documentation Binder.pdf • GE SGconfig software • Terminal (Tera Term, PuTTY) • WinSCP 14
- 15. Data Collection: D20MX You will need three manuals from the binder pdf: 1. 994-0140 D20MX Substation Controller Instruction Manual • Chapter 11: Troubleshooting 2. B014-1NUG Westmaint II+ for D20MX User’s Guide • Shows how to use the D20 console interface, menus, error and user logs 3. SWM0080 D20MX Shells User’s Guide 15
- 16. Data Collection: D20MX Error Log and User Log The error log tells what’s wrong with the configuration. The user log shows logins, logouts, and all user activity. Can be exported to CSV. This data also gets put into the syslog. 16
- 17. The power of the 3 Shells • You can access the shell remotely with SSH, but the most powerful access is through the front serial port. • Some of these commands require assistance from GE unless you really know what you are doing. 17
- 18. The main shell • D20M Shell is the main shell • Very similar to 68k monitor shell in older D20s • Incident Responders will want to collect data from this shell • All of the commands are explained in detail in the D20MX Shells UG 18
- 19. Data Collection: D20MX • Running configuration Use SGConfig, ConfigPro, or TeraTerm Very common task • Last-known good configuration Look in email, config database, engineer’s laptop, or it may be on a USB in the cabinet • Running firmware - img • CPU usage %, Memory usage % pr – performance monitor qr – query ram (volatile and nvram) • Running processes - qp 19
- 20. Data Collection: D20MX Serial analyzer • Very popular shell command (what’s Wireshark?) • In the D20M shell, use sa com# where # is the port number Turn on logging in TeraTerm beforehand to save the traffic This example is DNP3 20
- 21. Data Collection: D20MX • Dump memory si – shows system information including the memory base addresses d – dumps memory, but you have to tell it where to start and stop (only available over serial connection) • Hand the output to someone who understands VxWorks for analysis • Look for strings, injected code, or rootkits 21
- 22. Data Collection: D20MX VxWorks C Shell • OS level shell only accessible from the RS-232 port (access is denied from SSH) • Mainly used by GE customer support for troubleshooting VxWorks CMD Shell • OS 2nd level shell, accessed by typing cmd • VxWorks Kernel Shell Command Reference 6.9 • We can use some commands for forensics d (dump), netstat, ipf (firewall), syslog, show devices, show drivers, show history, ifconfig, route, and even pcap! 22
- 23. Example of live memory code injection & mem dump on the D20MX • Inject code via VxWorks C shell memory edit command m to simulate a rootkit [SCREENSHOTS OR VIDEO RECORDING HERE] • Collect volatile memory using the dump memory command d [SCREENSHOTS OR VIDEO RECORDING HERE] 23
- 24. Data Collection: VxWorks DFIR Tool – Problem 24 • We need tools that enable us to perform DFIR on ICS and embedded devices.
- 25. Data Collection: VxWorks DFIR Tool - Solution A collection of utilities that enable us to: • Read (and write) to memory on the device programmatically • We don’t want to have do dump memory manually • Cache the live memory locally • We shouldn’t need to fetch the same memory twice to check for different issues. • Compare the system image • Knowing the image is good is the first step toward looking somewhere else. • Provide the ability to read/write and cache device data to other tools • Tools can be written more generically when they don’t need to worry about how to get the data 25
- 26. Data Collection: VxWorks DFIR Tool - Cool Features • Can easily accommodate different transport mechanisms • Serial • TCP/Serial bridges • Protocols specific to other dumping utilities • Supports caching • Allows resuming if connectivity is lost • Sparse memory dumping • Comparative analysis works on • Anything that looks like a seek-able Python File Object • Cache Files • Memory Dumps • Sparse Memory Maps • Special Objects that request live memory 26
- 27. Data Collection: VxWorks DFIR Tool – Validating the host image 27
- 28. Data Collection: VxWorks DFIR Tool - Cool Projects We Used • CLE Loads Everything – (angr/CLE) • Loads our system image and provides an abstraction to a process memory space • Identifies architecture, endianness, etc. • Will soon support relocatable images (important for modules like appl.out) • Capstone - Nguyen Anh Quynh • Easy access to disassemble exactly what we needed 28
- 29. Data Collection: VxWorks DFIR Tool – Plans for the Future • Documentation • Expand the tool to work on other devices • Refine the scripts into easy-to-use modules • Moving the code to GitHub • Allow for feedback / feature requests / bug submissions 29
- 30. Data Collection: SEL-3530 RTAC Specs • 533 MHz Power PC • 1024 MB DDR2 ECC RAM • 2GB Storage • Embedded SEL Linux Tools to use • SEL-3530 RTAC Instruction Manual • SEL-5033 Instruction Manual • SEL-5033 software • Web Browser (Chrome, FireFox, etc) • Terminal for SSH (Tera Term, PuTTY) 30
- 31. Data Collection: SEL-3530 Digital data • Running configuration • User Accounts • Running firmware • CPU usage % • Memory usage % • POST checks • Reports (several) Physical Data • Password jumper 31
- 32. Data Collection: SEL-3530 These are the screenshots from when I sent a malformed DNP3 message that caused the RTAC to lose the configuration. https://ics-cert.us-cert.gov/advisories/ICSA-13-219-01 32
- 33. Data Collection: SEL-3530 • Section 3: Testing and Troubleshooting • Section 5: Web HMI and Logging • Section 6: Security • There are tags in the RTAC database that are assigned to help troubleshoot but are also useful for forensics as well. • Several log types • SOE report • IED report • syslog 33
- 34. Data Collection: SEL-3530 • Example of IED Report • Can be accessed via web or ODBC (MS Access) • No Linux Shell • Pros & cons • No SSH Interface with RTAC • SSH used for engineering remote access to relays 34
- 35. Data Collection: SEL-3530 • The RTAC can capture ethernet and serial traffic SEL-5033 software and the Comm Monitor • AG2012-15 Using Wireshark® to Troubleshoot Protocol Communications Issues on an RTAC DNP3 example • AG2015-15 Using Wireshark® to Decode RTAC Serial Line Messages and SEL Protocols SEL Fast Messaging example • SEL published several serial Wireshark dissectors SELFM, Telegyr 8979 35
- 36. For Further Reading… • HD Moore’s blogpost on VxWorks from 2010. • https://community.rapid7.com/community/metasploit/blog/2010/08/02/shiny-old-vxworks- vulnerabilities • Metasploit module for VxWorks remote memory dump (wdbrpc_memory_dump) • David Odell’s blogpost on QNX from 2012. • https://www.optiv.com/blog/pentesting-qnx-neutrino-rtos • ICS-CERT recommended practices for ICS forensics • https://ics-cert.us-cert.gov/sites/default/files/recommended_practices/Forensics_RP.pdf 36
- 37. For Further Reading… • Travis Goodspeed’s embedded device work on the MSP430 family • http://travisgoodspeed.blogspot.com/2007/11/ti-ez430-in-linux-with-iar-kickstart.html • http://travisgoodspeed.blogspot.com/2008/08/repurposing-ti-ez430u-part-3.html • Ralph Langner’s forensics work on Stuxnet payloads for Siemens PLCs • http://www.langner.com/en/wp-content/uploads/2013/11/To-kill-a-centrifuge.pdf • The Dec 23, 2015 Ukrainian Power Grid attack included writing over firmware of embedded Ethernet-serial converters. • https://ics.sans.org/media/E-ISAC_SANS_Ukraine_DUC_5.pdf 37
- 38. QUESTIONS? 38
Editor's Notes
- #4: Modified from the Mandiant IR services datasheet
- #5: 1. “During collection, data related to a specific event is identified, labeled, recorded, and collected, and its integrity is preserved. In the second phase, examination, forensic tools and techniques appropriate to the types of data that were collected are executed to identify and extract the relevant information from the collected data while protecting its integrity. Examination may use a combination of automated tools and manual processes. The next phase, analysis, involves analyzing the results of the examination to derive useful information that addresses the questions that were the impetus for performing the collection and examination. The final phase involves reporting the results of the analysis, which may include describing the actions performed, determining what other actions need to be performed, and recommending improvements to policies, guidelines, procedures, tools, and other aspects of the forensic process.” From NIST SP 800-86
- #9: You need to preserve the data if possible…even on embedded devices. There may be manual ways to dump the running configuration and maybe the volatile memory.
- #11: Physical data is important no matter if you have an equipment database or not.
- #14: When in doubt, read the manual! There usually is a section on troubleshooting, configuration or file transfer, and even shell commands.
- #25: Current Issues: Slow data Collection - We averaged 2300 bytes per second over serial - This would take us about 5 days to dump the full 1GB memory space Unknown protocol availability - Dumping data to our serial-connected RPi was not conducive to actually getting work done
- #26: I don’t need to know what you need to know in order to help. I can provide abstracted memory objects that simply let you read
- #27: We utilize the Special Objects that request live memory and Cache Files.
- #28: Here we see differences in the .text, .data, and .sdata sections. An attacker has injected code into the ipfirewall_start function that prevents the firewall from starting. Note: This is simply a “return 0;” The .data and .sdata were flagged as not matching the disk due to runtime data. Note: These were omitted to simplify the slide, not by some magical filtering that deemed the changes sane or safe.
- #29: Appl.out is a relocatable image which poses a problem due to absolute-address instructions that reference a relocatable section. These are the only two projects I ended up sticking with.
- #30: We need to check to see if there are any stops in place that prevent us from doing this or even saying we plan on doing this.
- #32: Most of these can be collected from the RTAC webpage or through the SEL-5033 software