BusyBox is an open source project that provides a stripped down implementation of around 400 common UNIX/Linux commands. It runs in a variety of POSIX environments such as Linux, Android, and FreeBSD, and is used in dockers.
Download and install busybox apk:
adb -d install BusyBox.apk
Usage example in Android forensics
Check root access:
su # ls /data
Check the mounted partitions on the device:
Choose the partitions you wish to image and note their paths, for example for the data partition, something like
Set up connection between the workstation and the mobile device, forwarding port
adb forward tcp:8080 tcp:8080
dd if=/dev/block/bootdevice/by-name/userdata | busybox nc -l -p 8080
nc 127.0.0.1 8080 > android_data.dd
Start analysis on the image disk, using sleuthkit tools or Autopsy.