ICSNPP-S7COMM

Industrial Control Systems Network Protocol Parsers (ICSNPP) - s7comm, s7comm-plus, and COTP.

Overview

ICSNPP-S7COMM is a Zeek plugin for parsing and logging fields within the s7comm, s7comm-plus, and COTP protocols.

This plugin was developed to be fully customizable, so if you would like to drill down into specific packets and log certain variables, add the logging functionality to scripts/icsnpp/s7comm/main.zeek. The functions within scripts/icsnpp/s7comm/main.zeek and src/events.bif should prove to be a good guide on how to add new logging functionality.

This parser currently produces five log files. These log files are defined in scripts/icsnpp/s7comm/main.zeek.

• cotp.log
• s7comm.log
• s7comm_read_szl.log
• s7comm_upload_download.log
• s7comm_plus.log

For additional information on these log files, see the Logging Capabilities section below.

Installation

Package Manager

This script is available as a package for Zeek Package Manger

zkg refresh
zkg install icsnpp-s7comm

If this package is installed from ZKG it will be added to the available plugins. This can be tested by running zeek -N. If installed correctly you will see ICSNPP::S7COMM.

If you have ZKG configured to load packages (see @load packages in quickstart guide), this plugin and scripts will automatically be loaded and ready to go. ZKG Quickstart Guide

If you are not using site/local.zeek or another site installation of Zeek and just want to run this package on a packet capture you can add icsnpp/s7comm to your command to run this plugin's scripts on the packet capture:

git clone https://github.com/cisagov/icsnpp-s7comm.git
zeek -Cr icsnpp-s7comm/tests/traces/s7comm_plus_example.pcap icsnpp/s7comm

Manual Install

To install this package manually, clone this repository and run the configure and make commands as shown below.

git clone https://github.com/cisagov/icsnpp-s7comm.git
cd icsnpp-s7comm/
./configure
make

If these commands succeed, you will end up with a newly create build directory. This contains all the files needed to run/test this plugin. The easiest way to test the parser is to point the ZEEK_PLUGIN_PATH environment variable to this build directory.

export ZEEK_PLUGIN_PATH=$PWD/build/
zeek -N # Ensure everything compiled correctly and you are able to see ICSNPP::S7COMM

Once you have tested the functionality locally and it appears to have compiled correctly, you can install it system-wide:

sudo make install
unset ZEEK_PLUGIN_PATH
zeek -N # Ensure everything installed correctly and you are able to see ICSNPP::S7COMM

To run this plugin in a site deployment you will need to add the line @load icsnpp/s7comm to your site/local.zeek file in order to load this plugin's scripts.

If you are not using site/local.zeek or another site installation of Zeek and just want to run this package on a packet capture you can add icsnpp/s7comm to your command to run this plugin's scripts on the packet capture:

zeek -Cr icsnpp-s7comm/tests/traces/s7comm_plus_example.pcap icsnpp/s7comm

If you want to deploy this on an already existing Zeek implementation and you don't want to build the plugin on the machine, you can extract the ICSNPP_S7comm.tgz file to the directory of the established ZEEK_PLUGIN_PATH (default is ${ZEEK_INSTALLATION_DIR}/lib/zeek/plugins/).

tar xvzf build/ICSNPP_S7comm.tgz -C $ZEEK_PLUGIN_PATH 

Logging Capabilities

COTP Log (cotp.log)

Overview

This log captures COTP information for every COTP packet and logs it to cotp.log.

Fields Captured

Field	Type	Description
ts	time	Timestamp
uid	string	Unique ID for this Connection
id	conn_id	Default Zeek Connection Info (IP addresses, ports)
is_orig	bool	True if the packet is sent from the originator
pdu_code	string	COTP PDU Type Code (in hex)
pdu_name	string	COTP PDU Name

S7COMM Header Log (s7comm.log)

Overview

This log captures s7comm header information for every s7comm packet and logs it to s7comm.log.

Fields Captured

Field	Type	Description
ts	time	Timestamp
uid	string	Unique ID for this Connection
id	conn_id	Default Zeek Connection Info (IP addresses, ports)
is_orig	bool	True if the packet is sent from the originator
rosctr_code	count	Remote Operating Service Control Code (in hex)
rosctr_name	string	Remote Operating Service Control Name
pdu_reference	count	Reference ID Used to Link Requests to Responses
function_code	string	Parameter Function Code (in hex)
function_name	string	Parameter Function Name
subfunction_code	string	User-Data Subfunction Code (in hex)
subfunction_name	string	User-Data Subfunction Name
error_class	string	Error Class Name
error_code	string	Error Code within Error Class

S7COMM Read-SZL Log (s7comm_read_szl.log)

Overview

This log captures information for the common S7Comm Read-SZL function. This data is logged to s7comm_read_szl.log.

Fields Captured

Field	Type	Description
ts	time	Timestamp
uid	string	Unique ID for this Connection
id	conn_id	Default Zeek Connection Info (IP addresses, ports)
pdu_reference	count	Reference ID Used to Link Requests to Responses
method	string	Request or Response
szl_id	string	SZL ID (in hex)
szl_id_name	string	Meaning of SZL ID
szl_index	string	SZL Index (in hex)
return_code	string	Return Code (in hex)
return_code_name	string	Meaning of Return Code

S7COMM Upload-Download Log (s7comm_upload_download.log)

Overview

This log captures information for the S7Comm Upload and Download functions (see list below). This data is logged to s7comm_upload_download.log.:

• Start Upload
• Upload
• End Upload
• Request Download
• Download Block
• Download Ended

Fields Captured

Field	Type	Description
ts	time	Timestamp
uid	string	Unique ID for this Connection
id	conn_id	Default Zeek Connection Info (IP addresses, ports)
rosctr	count	Remote Operating Service Control
pdu_reference	count	Reference ID Used to Link Requests to Responses
function_code	count	Parameter Function Code
function_status	count	Function Status
session_id	count	Session ID
blocklength	count	Length of Block to Upload/Download
filename	string	Filename of Block to Upload/Download
block_type	string	Block Type to Upload/Download
block_number	string	Block Number to Upload/Download
destination_filesystem	string	Destination Filesystem of Upload/Download

S7COMM-PLUS Log (s7comm_plus.log)

Overview

This log captures s7comm-plus header information for every s7comm-plus packet and logs it to s7comm_plus.log.

Fields Captured

Field	Type	Description
ts	time	Timestamp
uid	string	Unique ID for this Connection
id	conn_id	Default Zeek Connection Info (IP addresses, ports)
is_orig	bool	True if the packet is sent from the originator
version	count	S7comm-plus Version
opcode	string	Opcode Code (in hex)
opcode_name	string	Opcode Name
function_code	string	Opcode Function Code (in hex)
function_name	string	Opcode Function Name

S7COMM File Extraction

S7COMM contains two functions for sending and receiving files: Upload and Download-Block. This plugin will extract files sent via these two functions and pass the extracted files to Zeek's file analysis framework.

ICSNPP Packages

All ICSNPP Packages:

• ICSNPP

Full ICS Protocol Parsers:

• BACnet
  • Full Zeek protocol parser for BACnet (Building Control and Automation)
• BSAP
  • Full Zeek protocol parser for BSAP (Bristol Standard Asynchronous Protocol) over IP
  • Full Zeek protocol parser for BSAP Serial comm converted using serial tap device
• Ethercat
  • Full Zeek protocol parser for Ethercat
• Ethernet/IP and CIP
  • Full Zeek protocol parser for Ethernet/IP and CIP
• Genisys
  • Full Zeek protocol parser for Genisys
• OPCUA-Binary
  • Full Zeek protocol parser for OPC UA (OPC Unified Architecture) - Binary
• S7Comm
  • Full Zeek protocol parser for S7comm, S7comm-plus, and COTP

Updates to Zeek ICS Protocol Parsers:

• DNP3
  • DNP3 Zeek script extending logging capabilities of Zeek's default DNP3 protocol parser
• Modbus
  • Modbus Zeek script extending logging capabilities of Zeek's default Modbus protocol parser

Other Software

Idaho National Laboratory is a cutting edge research facility which is a constantly producing high quality research and software. Feel free to take a look at our other software and scientific offerings at:

Primary Technology Offerings Page

Supported Open Source Software

Raw Experiment Open Source Software

Unsupported Open Source Software

License

Copyright 2022 Battelle Energy Alliance, LLC

Licensed under the 3-Part BSD (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

https://opensource.org/licenses/BSD-3-Clause

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Licensing

This software is licensed under the terms you may find in the file named "LICENSE" in this directory.