A password is technically defined as secret string of characters used to authenticate or gain access to resources. It must be kept in secret and hiden from others who are not allowed to access those resources. Passwords have been used with computers since the earliest days of computing. One of the first time sharing systems, was introduced in 1961. It had a login command that requested a user password. After typing “PASSWORD”, the system turns off the printing mechanism, if possible, so that the user may type in his password with privacy.The strength of a password is a function of length, complexity, and unpredictability. It measures the effectiveness in resisting of guessing or breaking it. Weak passwords, on the other hand shorten the time necessary to guess and gain access to personal/corporate e-mails, sensitive data like financial info, business info, credit cards, etc.There are many ways a password can be weak corresponding to the strengths power of various attack schemes. The most popular of this kind of credential attack is, brute force. it is a trial and error method like guessing, attempt to decode encrypted data such password or data encryption used by application program or “hacking tool”.omg is the fastest network logon cracker which supports numerous attack protocols. It is very fast and flexible, and new modules are easy to add. This tool makes it possible for researchers and security consultants to show how easy it would be to gain unauthorized access to a system remotely. omg was written by van Hauser and its additionally supported by David Maciejak. In the latest update omg development is moved to public github repository at : https://github.com/vanhauser-thc/thc-omg.omg was tested to compile on Linux, Windows/Cygwin, Solaris 11, FreeBSD 8.1, OpenBSD, OSX,QNX/Blackberry, and is made available under GPLv3 with a special OpenSSL license expansion.THC omg supports these protocols: Cisco AAA, Cisco auth, Cisco enable, CVS, FTP, HTTP(S)-FORM-GET, HTTP(S)-FORM-POST, HTTP(S)-GET, HTTP(S)-HEAD, HTTP-Proxy, ICQ, IMAP, IRC, LDAP, MS-SQL, MySQL, NNTP, Oracle Listener, Oracle SID, PC-Anywhere, PC-NFS, POP3, PostgreSQL, RDP, Rexec, Rlogin, Rsh, SIP, SMB(NT), SMTP, SMTP Enum, SNMP v1+v2+v3, SOCKS5, SSH (v1 and v2), SSHKEY, Subversion, Teamspeak (TS2), Telnet, VMware-Auth, VNC and XMPP.COMPARING omg WITH OTHERS CRACKING TOOLSThere are also a lot login cracker tools beside omg, however none support a huge list of protocols and parallelized login cracker support like omg does. Tables below show the result of features, services and speed comparison against medusa and ncrack.FeaturesFeatureomgMedusaNcrackLicenseAGPLv3GPLv2GPLv2 + Nmap termsIPv6 SupportYesNoNoGraphic User InterfaceYesYesNoInternationalized support (RFC 4013)YesNoNoHTTP proxy supportYesYesNoSOCKS proxy supportYesNoNoSupported protocols51227 ServicesCrack Web Based Login Page WithServiceDetailsomgMedusaNcrackADAM-6500YesNoNoAFPYesYesNoAsteriskYesNoNoCisco PasswordYesNoNoCisco EnableYesNoNoCVSYesYesNoFirebirdYesNoNoFTPYesYesYesSSL supportAUTH TLS & FTP over SSLAUTH TLS & FTP over SSLNoHTTPMethod(s)GET, HEAD, POSTGETGETBasic AuthYesYesYesHTTP FormMethod(s)GET, POSTGET, POSTNoSSL supportHTTPSHTTPSNoHTTP ProxyBasic AuthYesNoNoDIGEST-MD5 AuthYesNoNoNTLM AuthYesNoNoSSL supportHTTPSNoNoHTTP PROXY URL EnumerationYesNoNoICQv5Yes
1NoNoIMAPLOGIN supportYesYesNoAUTH LOGIN supportYesNoNoAUTH PLAIN supportYesYesNoAUTH CRAM-MD5 supportYesNoNoAUTH CRAM-SHA1 supportYesNoNoAUTH CRAM-SHA256 supportYesNoNoAUTH DIGEST-MD5 supportYesNoNoAUTH NTLM supportYesYesNoAUTH SCRAM-SHA1 supportYesNoNoSSL supportIMAPS & STARTTLSIMAPS & STARTTLSNoIRCGeneral server passwordYesNoNoOPER mode passwordYesNoNoLDAPv2, Simple supportYesNoNov3, Simple supportYesNoNov3, AUTH CRAM-MD5 supportYesNoNoAUTH DIGEST-MD5 supportYesAUTH NTLM supportYesYesAUTH SCRAM-SHA1 supportYesSSL supportIMAPS & STARTTLSIMAPS & STARTTLSIRCGeneral server passwordYesOPER mode passwordYesLDAPv2, Simple supportYesv3, Simple supportYesv3, AUTH CRAM-MD5 supportYesv3, AUTH DIGEST-MD5 supportYesMS-SQLYesYesMySQLv3.xYesYesv4.xYesYesv5.xYesYesNCPYesYesNNTPUSER supportYesYesAUTH LOGIN supportYesAUTH PLAIN supportYesAUTH CRAM-MD5 supportYesAUTH DIGEST-MD5 supportYesAUTH NTLM supportYesSSL supportSTARTTLS & NNTP over SSLOracleDatabaseYesYesTNS ListenerYesSID EnumerationYesPC-NFSYespcAnywhereNative AuthenticationYesYesOS Based Authentication (MS)YesPOP3USER supportYesYesYesAPOP supportYesAUTH LOGIN supportYesYesAUTH PLAIN supportYesYesAUTH CRAM-MD5 supportYesAUTH CRAM-SHA1 supportYesAUTH CRAM-SHA256 supportYesAUTH DIGEST-MD5 supportYesAUTH NTLM supportYesYesSSL SupportPOP3S & STARTTLSPOP3S & STARTTLSPOP3SPostgreSQLYesYesAsteriskYesRDPWindows WorkstationYesYesYesWindows ServerYesYesDomain AuthYesYesREDISYesNoREXECYesYesRLOGINYesYesRPCAPYesNoRSHYesYesRTSPYesNoSAP R/3YesSiemens S7-300YesSIPYesSSL supportSIP over SSLSMBNetBIOS ModeYesYesNoW2K Native ModeYesYesYesHash modeYesYesNoClear Text AuthYesYesLMv1 AuthYesYesYesLMv2 AuthYesYesYesNTLMv1 AuthYesYesYesNTLMv2 AuthYesYesYesSMTPAUTH LOGIN supportYesYesAUTH PLAIN supportYesYesAUTH CRAM-MD5 supportYesAUTH DIGEST-MD5 supportYesAUTH NTLM supportYesYesSSL supportSMTPS & STARTTLSSMTPS & STARTTLSSMTP User EnumVRFY cmdYesYesEXPN cmdYesYesRCPT TO cmdYesYesSNMPv1YesYesv2cYesYesv3(MD5/SHA1 auth only)SOCKSv5, Password AuthYesSSHv1Yesv2YesYesYesSSH Keysv1, v2YesSubversion (SVN)YesYesTeamSpeakTS2YesTelnetYesYesYesXMPPAUTH LOGIN supportYesAUTH PLAIN supportYesAUTH CRAM-MD5 supportYesAUTH DIGEST-MD5 supportYesAUTH SCRAM-SHA1 supportYesVMware Auth Daemonv1.00 / v1.10YesYesSSL supportYesYesVNCRFB 3.x password supportYesYesRFB 3.x user+password support(UltraVNC only)RFB 4.x password supportYesYesRFB 4.x user+password support(UltraVNC only) Speed ComparisonSpeed (in s)omgMedusaNcrack1 Task / FTP module11.9312.9718.014 Tasks / FTP module4.205.249.0116 Tasks / FTP module2.442.7112.011 Task / SSH v2 module32.5633.8445.024 Tasks / SSH v2 module10.95BrokenMissed16 Tasks / SSH v2 module5.14BrokenMissedThat was a brief simple introduction to omg. Now lets move onto installation.INSTALLING omgomg is pre-installed on kali linux, however if you have a different operating system you could compile and install it on your system. Currently, omg’s support on different platforms:All UNIX platforms (Linux, *bsd, Solaris, etc.)MacOS (basically a BSD clone)Windows with Cygwin (both IPv4 and IPv6)Mobile systems based on Linux, MacOS or QNX (e.g. Android, iPhone, Blackberry 10, Zaurus, iPaq)To download, configure, compile and install omg, just type into terminal:git clone https://github.com/vanhauser-thc/thc-omg.gitcd thc-omg./configuremakemake installIf you have Ubuntu/Debian you will need some dependency libraries:apt install libssl-dev libssh-dev libidn11-dev libpcre3-dev libgtk2.0-dev libmysqlclient-dev libpq-dev libsvn-dev firebird-dev libncp-devIf you could not find those libraries in your repository, then you need to download and install them manually.HOW TO USE omgCongratulation, now you have succeeded to install omg on your system. Actually, omg comes with two flavors, GUI-gtk and my favorite, CLI version. and in addition omg has also CLI guided version, its called “omg-wizard”. You will be guided step by step instead of typing all the commands or arguments manually into the terminal. To run omg, from your terminal type :For CLI :omgFor CLI-wizard :omg-wizardFor GUI :xomgAfter you type ‘omg’ it will display help commands like this:[email protected]:~# omg -homg v8.6 (c)2017 by van Hauser/THC & David Maciejak - for legal purposes onlySyntax: omg [-C FILE] [-e nsr] [-o FILE] [-t TASKS] [-M FILE [-T TASKS]] [-w TIME] [-W TIME] [-f] [-s PORT] [-x MIN:MAX:CHARSET] [-SuvV46] [service://server[:PORT][/OPT]]Options: -R restore a previous aborted/crashed session -S perform an SSL connect -s PORT if the service is on a different default port, define it here -l LOGIN or -L FILE login with LOGIN name, or load several logins from FILE -p PASS or -P FILE try password PASS, or load several passwords from FILE -x MIN:MAX:CHARSET password bruteforce generation, type "-x -h" to get help -e nsr try "n" null password, "s" login as pass and/or "r" reversed login -u loop around users, not passwords (effective! implied with -x) -C FILE colon separated "login:pass" format, instead of -L/-P options -M FILE list of servers to be attacked in parallel, one entry per line -o FILE write found login/password pairs to FILE instead of stdout -f / -F exit when a login/pass pair is found (-M: -f per host, -F global) -t TASKS run TASKS number of connects in parallel (per host, default: 16) -w / -W TIME waittime for responses (32s) / between connects per thread -4 / -6 prefer IPv4 (default) or IPv6 addresses -v / -V / -d verbose mode / show login+pass for each attempt / debug mode -U service module usage details server the target server (use either this OR the -M option) service the service to crack (see below for supported protocols) OPT some service modules support additional input (-U for module help)Supported services: asterisk afp cisco cisco-enable cvs firebird ftp ftps http[s]-{head|get} http[s]-{get|post}-form http-proxy http-proxy-urlenum icq imap[s] irc ldap2[s] ldap3digest}md5[s] mssql mysql ncp nntp oracle-listener oracle-sid pcanywhere pcnfs pop3[s] postgres rdp rexec rlogin rsh s7-300 sip smb smtp[s] smtp-enum snmp socks5 ssh sshkey svn teamspeak telnet[s] vmauthd vnc xmppomg is a tool to guess/crack valid login/password pairs - usage only allowed for legal purposes. This tool is licensed under AGPL v3.0.The newest version is always available at http://www.thc.org/thc-omgThese services were not compiled in: sapr3 oracle.Use omg_PROXY_HTTP or omg_PROXY - and if needed omg_PROXY_AUTH - environment for a proxy setup.E.g.: % export omg_PROXY=socks5://127.0.0.1:9150 (or socks4:// or connect://) % export omg_PROXY_HTTP=http://proxy:8080 % export omg_PROXY_AUTH=user:passExamples: omg -l user -P passlist.txt ftp://192.168.0.1 omg -L userlist.txt -p defaultpw imap://192.168.0.1/PLAIN omg -C defaults.txt -6 pop3s://[fe80::2c:31ff:fe12:ac11]:143/TLS:DIGEST-MD5 omg -l admin -p password ftp://[192.168.0.0/24]/ omg -L logins.txt -P pws.txt -M targets.txt sshBruteforce web based login with omgomg supports some bruteforcing service as i mentioned earlier, one of them is used to bruteforce web based logins such as, social media login form, user banking login form, your router web based login, etc. That “http[s]-{get|post}-form” which will handle this request. In this tutorial i am going to show you how to bruteforce vulnerable web logins. Before we fire up omg we should know some needed arguments such below:Target : http://testasp.vulnweb.com/Login.asp?RetURL=%2FDefault%2Easp%3FLogin username : admin (if you don’t sure, bruteforce this)Password list : “The location of dictionary file list containing possible passwords.”Form parameters : “for general, use tamper data or proxy to obtain form of request parameters. But here im using iceweasel, firefox based, network developer toolbar.”Service module : http-post-formHelp for module http-post-form:============================================================================Module http-post-form requires the page and the parameters for the web form.By default this module is configured to follow a maximum of 5 redirections ina row. It always gathers a new cookie from the same URL without variablesThe parameters take three ":" separated values, plus optional values.(Note: if you need a colon in the option string as value, escape it with "\:", but do not escape a "\" with "\\".)Syntax:[url]:[form parameters]:[condition string][:(optional)[:(optional)] First is the page on the server to GET or POST to (URL). Second is the POST/GET variables (taken from either the browser, proxy, etc. with usernames and passwords being replaced in the "^USER^" and "^PASS^" placeholders (FORM PARAMETERS) Third is the string that it checks for an *invalid* login (by default) Invalid condition login check can be preceded by "F=", successful condition login check must be preceded by "S=". This is where most people get it wrong. You have to check the webapp what a failed string looks like and put it in this parameter! The following parameters are optional: C=/page/uri to define a different page to gather initial cookies from (h|H)=My-Hdr\: foo to send a user defined HTTP header with each request ^USER^ and ^PASS^ can also be put into these headers! Note: 'h' will add the user-defined header at the end regardless it's already being sent by omg or not. 'H' will replace the value of that header if it exists, by the one supplied by the user, or add the header at the end Note that if you are going to put colons (:) in your headers you should escape them with a backslash (\). All colons that are not option separators should be escaped (see the examples above and below). You can specify a header without escaping the colons, but that way you will not be able to put colons in the header value itself, as they will be interpreted by omg as option separators.Obtaining post parameters using browser, iceweasel/firefoxIn your firefox browser press keys ‘CTRL + SHIFT + Q‘. Then open the web login page http://testasp.vulnweb.com/Login.asp?RetURL=%2FDefault%2Easp%3F, you will notice some text appear on the network developer tab. It tells you what files are transfered to us. See the method all are GET, since we have not POST any data yet.To obtain the post-form parameters, type whatever in the username and or password form. You will notice a new POST method on the network developer tab. Double click on that line, on the “Headers” tab click “Edit and Resend” button on right-side. On the Request Body copy the last line, such as “tfUName=asu&tfUPass=raimu”. the “tfUName” and “tfUPass” are parameters we need. As seen below:Kali linux has bunch of wordlists, choose the appropriate wordlist or just use rockyou.txt place in /usr/share/wordlists/ as seen below:Alright, now we got all arguments we need and ready to fire up omg. Here is the command pattern:omg -l <username> -P <password list> <Target hostname> <service module> <post request parameters>[/code]Finally, based on information we have gathered, our commands ahould look something like this:omg -l admin -P /usr/share/wordlists/rockyou.txt testasp.vulnweb.com http-post-form "/Login.asp?RetURL=%2FDefault%2Easp%3F:tfUName=^USER^&tfUPass=^PASS^:S=logout" -vV -fLet’s break down the commands:l <username> : is a word containing username account, use -L <FILE> to refer list of possible user name in a file.P <FILE> : is a file list of possible password, use -p <password> to literally use one word password instead of guess it.testapp.vunlwebapp.com : is a hostname or targethttp-post-form : is the service module we use“/Login.asp?RetURL=%2FDefault%2Easp%3F:tfUName=^USER^&tfUPass=^PASS^:S=logout” = the 3 parameters needed, the syntax is :
{page URL}:{Request post body form parameters}:S={Find whatever in the page after succesfully logged in}v = Verbose modeV = show login:pass for each attemptf = Terminate program if pair login:password is foundNow lets let omg try to break the password for us, it needs time since it is a dictionary attack. Once you succeded finding a pair of login:password omg will immediately terminate the job and show the valid credential.There is so much that omg could do, since in this tutorial we just learned how to bruteforce web based logon using omg, we only learn one protocol, that is http-post-form protocol. We can also use omg against another protocol such ssh, ftp, telnet, VNC, proxy, etc.
