A binary may support one or more of the following functions:
It can be used to break out from restricted environments by spawning an interactive system shell.
It can be used to break out from restricted environments by running non-interactive system commands.
It can send back a reverse shell to a listening attacker to open a remote network access.
It can send back a non-interactive reverse shell to a listening attacker to open a remote network access.
It can bind a shell to a local port to allow remote network access.
It can bind a non-interactive shell to a local port to allow remote network access.
It can exfiltrate files on the network.
It can download remote files.
It writes data to files, it may be used to do privileged writes or write files outside a restricted file system.
It reads data from files, it may be used to do privileged reads or disclose files outside a restricted file system.
It loads shared libraries that may be used to run code in the binary execution context.
It runs with the SUID bit set and may be exploited to access the file
system, escalate or maintain access with elevated privileges working as a
SUID backdoor. If it is used to run sh -p, omit the -p argument on systems
like Debian that allow the default sh shell to run with SUID privileges.
It runs in privileged context and may be used to access the file system,
escalate or maintain access with elevated privileges if enabled on sudo.
It can manipulate its process UID and can be used on Linux as a backdoor to maintain
elevated privileges with the CAP_SETUID capability set. This also works when executed
by another binary with the capability set.
It runs with the SUID bit set and may be exploited to access the file
system, escalate or maintain access with elevated privileges working as a
SUID backdoor. If it is used to run commands it only works on systems
like Debian that allow the default sh shell to run with SUID privileges.