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WannaCrypt Ransomware

Published 13/05/2017 / by jeff / Leave a Comment
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In what has been big news over the past 24 hours.  Especially here in the UK is that the NHS has been hit with a large ransomware attack.

http://www.bbc.co.uk/news/technology-39901382

http://blog.talosintelligence.com/2017/05/wannacry.html?m=1

This is a pretty good write up of what was known at the time.

There have been easy fixes for this available for the past 2 months and it was just a matter of time until the tools that were developed by our American Friends, that they would be used against the general public.

Hopefully this is lessons learned for many organisations, and they realise that patching and running fairly up to date operating systems is important and not just something to achieve compliance.

Few more articles that contain good information about these events.

https://www.troyhunt.com/everything-you-need-to-know-about-the-wannacrypt-ransomware/

https://www.malwaretech.com/2017/05/how-to-accidentally-stop-a-global-cyber-attacks.html

 

Also of note.

wannadecrypt

 

If you use intitle:”index of” “@WanaDecryptor@.exe” as a search on google, at the time of this update there are 67 results.

Not a good weekend for the world of IT admins.

The github link referenced below is being kept up today and contains some very good and useful information.

 

WannaCry|WannaDecrypt0r NSA-Cyberweapon-Powered Ransomware Worm

  • Virus Name: WannaCrypt, WannaCry, WanaCrypt0r, WCrypt, WCRY
  • Vector: All Windows versions before Windows 10 are vulnerable if not patched for MS-17-010. It uses EternalBlue MS17-010 to propagate.
  • Ransom: between $300 to $600. There is code to ‘rm’ (delete) files in the virus. Seems to reset if the virus crashes.
  • Backdooring: The worm loops through every RDP session on a system to run the ransomware as that user. It also installs the DOUBLEPULSAR backdoor. It corrupts shadow volumes to make recovery harder. (source: malwarebytes)
  • Kill switch: If the website www.iuqerfsodp9ifjaposdfjhgosurijfaewrwergwea.com is up the virus exits instead of infecting the host. (source: malwarebytes). This domain has been sinkholed, stopping the spread of the worm. Will not work if proxied (source).

update: A minor variant of the virus has been found, it looks to have had the killswitch hexedited out. Not done by recompile so probably not done by the original malware author. On the other hand that is the only change: the encryption keys are the same, the bitcoin addresses are the same. On the other hand it is corrupt so the ransomware aspect of it doesn’t work – it only propagates.

SECURITY BULLETIN AND UPDATES HERE: https://technet.microsoft.com/en-us/library/security/ms17-010.aspx

Microsoft first patch for XP since 2014: https://blogs.technet.microsoft.com/msrc/2017/05/12/customer-guidance-for-wannacrypt-attacks/

Killswitch source: https://blog.malwarebytes.com/threat-analysis/2017/05/the-worm-that-spreads-wanacrypt0r/ https://www.malwaretech.com/2017/05/how-to-accidentally-stop-a-global-cyber-attacks.html

Exploit details: https://zerosum0x0.blogspot.com/2017/04/doublepulsar-initial-smb-backdoor-ring.html

Vulnerable/Not Vulnerable

To be infected requires the SMB port (445) to be open, or the machine already infected with DOUBLEPULSAR (and killswitch not registered or somehow blocked, or the network accessing it through a proxy).

The MS17-010 patch fixes the vulnerability.

  • Windows XP: Doesn’t spread. If run manually, can encrypt files.
  • Windows 7,8,2008: can spread unpatched, can encrypt files.
  • Windows 10: Doesn’t spread. Even though Windows 10 does have the faulty SMB driver.
  • Linux: Doesn’t spread. If run manually with wine, can encrypt files.

Infections

Informative Tweets

Cryptography details

  • Each infection generates a new RSA-2048 keypair.
  • The public key is exported as blob and saved to 00000000.pky
  • The private key is encrypted with the ransomware public key and saved as 00000000.eky
  • Each file is encrypted using AES-128-CBC, with a unique AES key per file.
  • Each AES key is generated CryptGenRandom.
  • The AES key is encrypted using the infection specific RSA keypair.

The RSA public key used to encrypt the infection specific RSA private key is embedded inside the DLL and owned by the ransomware authors.

https://pastebin.com/aaW2Rfb6 even more in depth RE information by cyg_x1!!

Bitcoin ransom addresses

3 addresses hard coded into the malware.

C&C centers

  • gx7ekbenv2riucmf.onion
  • 57g7spgrzlojinas.onion
  • xxlvbrloxvriy2c5.onion
  • 76jdd2ir2embyv47.onion
  • cwwnhwhlz52maqm7.onion

Languages

All language ransom messages available here: https://transfer.sh/y6qco/WANNACRYDECRYPTOR-Ransomware-Messages-all-langs.zip

m_bulgarian, m_chinese (simplified), m_chinese (traditional), m_croatian, m_czech, m_danish, m_dutch, m_english, m_filipino, m_finnish, m_french, m_german, m_greek, m_indonesian, m_italian, m_japanese, m_korean, m_latvian, m_norwegian, m_polish, m_portuguese, m_romanian, m_russian, m_slovak, m_spanish, m_swedish, m_turkish, m_vietnamese

File types

There are a number of files and folders wannacrypt will avoid. Some because it’s entirely pointless and others because it might destabilize the system. During scans, it will search the path for the following strings and skip over if present:

  • “Content.IE5”
  • “Temporary Internet Files”
  • ” This folder protects against ransomware. Modifying it will reduce protection”
  • “\Local Settings\Temp”
  • “\AppData\Local\Temp”
  • “\Program Files (x86)”
  • “\Program Files”
  • “\WINDOWS”
  • “\ProgramData”
  • “\Intel”
  • “$”

The filetypes it looks for to encrypt are:

.doc, .docx, .xls, .xlsx, .ppt, .pptx, .pst, .ost, .msg, .eml, .vsd, .vsdx, .txt, .csv, .rtf, .123, .wks, .wk1, .pdf, .dwg, .onetoc2, .snt, .jpeg, .jpg, .docb, .docm, .dot, .dotm, .dotx, .xlsm, .xlsb, .xlw, .xlt, .xlm, .xlc, .xltx, .xltm, .pptm, .pot, .pps, .ppsm, .ppsx, .ppam, .potx, .potm, .edb, .hwp, .602, .sxi, .sti, .sldx, .sldm, .sldm, .vdi, .vmdk, .vmx, .gpg, .aes, .ARC, .PAQ, .bz2, .tbk, .bak, .tar, .tgz, .gz, .7z, .rar, .zip, .backup, .iso, .vcd, .bmp, .png, .gif, .raw, .cgm, .tif, .tiff, .nef, .psd, .ai, .svg, .djvu, .m4u, .m3u, .mid, .wma, .flv, .3g2, .mkv, .3gp, .mp4, .mov, .avi, .asf, .mpeg, .vob, .mpg, .wmv, .fla, .swf, .wav, .mp3, .sh, .class, .jar, .java, .rb, .asp, .php, .jsp, .brd, .sch, .dch, .dip, .pl, .vb, .vbs, .ps1, .bat, .cmd, .js, .asm, .h, .pas, .cpp, .c, .cs, .suo, .sln, .ldf, .mdf, .ibd, .myi, .myd, .frm, .odb, .dbf, .db, .mdb, .accdb, .sql, .sqlitedb, .sqlite3, .asc, .lay6, .lay, .mml, .sxm, .otg, .odg, .uop, .std, .sxd, .otp, .odp, .wb2, .slk, .dif, .stc, .sxc, .ots, .ods, .3dm, .max, .3ds, .uot, .stw, .sxw, .ott, .odt, .pem, .p12, .csr, .crt, .key, .pfx, .der

credit herulume, thanks for extracting this list from the binary.

more details came from https://pastebin.com/xZKU7Ph1 thanks to cyg_x11

Some other interesting strings

credit: nulldot https://pastebin.com/0LrH05y2

Encrypted file format

typedef struct _wc_file_t {
    char     sig[WC_SIG_LEN]     // 64 bit signature WANACRY!
    uint32_t keylen;             // length of encrypted key
    uint8_t  key[WC_ENCKEY_LEN]; // AES key encrypted with RSA
    uint32_t unknown;            // usually 3 or 4, unknown
    uint64_t datalen;            // length of file before encryption, obtained from GetFileSizeEx
    uint8_t *data;               // Ciphertext Encrypted data using AES-128 in CBC mode
} wc_file_t;

credit for reversing this file format info: cyg_x11.

Vulnerability disclosure

The specific vulnerability that it uses to propagate is ETERNALBLUE.

This was developed by “equation group” an exploit developer group associated with the NSA and leaked to the public by “the shadow brokers”. Microsoft fixed this vulnerability March 14, 2017. They were not 0 days at the time of release.

view raw

Wannacrypt0r-FACTSHEET.md

hosted with ❤ by GitHub

 

Protecting customers and evaluating risk – Microsoft

Published 15/04/2017 / by jeff / Leave a Comment
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In what feels like perfect timing from Microsoft, it seems they had already released patches for some if not all of the exploits released these past few days by the file dump by the ShadowBrokers.

 

Code Name Solution
“EternalBlue” Addressed by MS17-010
“EmeraldThread” Addressed by MS10-061
“EternalChampion” Addressed by CVE-2017-0146 & CVE-2017-0147
“ErraticGopher” Addressed prior to the release of Windows Vista
“EsikmoRoll” Addressed by MS14-068
“EternalRomance” Addressed by MS17-010
“EducatedScholar” Addressed by MS09-050
“EternalSynergy” Addressed by MS17-010
“EclipsedWing” Addressed by MS08-067

 

This has been taken straight from the Microsoft Blog.

Regardless how this happens does not matter, it is just good to know that most if not all of these issues released are patched.

***On 17th April, we have a news article on the BBC that actually covers this story by Microsoft

http://www.bbc.co.uk/news/technology-39620534

It is good to see that we are getting better as an industry to fix and patch these exploits.

 

 

NSA Tools in the Wild

Published 14/04/2017 / by jeff / Leave a Comment
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Further apparent NSA tools have been released and this time there is alot more information contained with the files.  This tool in particular looks quite similar to metasploit.

@hackerfantastic have been investigating these tools and posting their findings, I believe there are going to be fun times in the next week or so!

Infected Webpage

Published 12/04/2017 / by jeff / Leave a Comment
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hxxp://petroffpianostudio[.]com/ (This may now be cleaned up at the time of posting)

It looks like the the aforementioned webpage is infected with a redirect to download suspect files

Traffic observed after the infection suggests that it will attempt to download executable files from a few different locations.

hxxp://talk-of-the-tyne.co.uk/download1264/
hxxp://willy.pro.br/download3299/
hxxp://freight.eu.com/download3696/

The analysis of the files on hybrid analysis does confirm that these are malicious files

https://www.hybrid-analysis.com/sample/e8d2f149de58eb45b398a84d6d27d568ab1d239584edcb55531fe11da2f9c51b?environmentId=100

Once the executable file is on the host machine, it then attempts to call out to the following

173.230.137.155
206.214.220.79

Upon further analysis we have another file which has been downloaded from the following location

hxxp://matchpointpro.com/lDu52756eeJMW/

https://www.virustotal.com/en/file/4b97fa91d9f33392fde84a2af3500a78621a71b80b3d3486a7b70cdd47187ce3/analysis/1492020556/

https://www.hybrid-analysis.com/sample/4b97fa91d9f33392fde84a2af3500a78621a71b80b3d3486a7b70cdd47187ce3?environmentId=100

I revisited the links later in the day and have a bit more details, we can see they are still serving executable files. Chrome is now blocking and suggesting these files are malicious, and also so is internet explorer. I have not tried them on firefox at this time.

GET /download3299/ HTTP/1.1
Accept: application/x-ms-application, image/jpeg, application/xaml+xml, image/gif, image/pjpeg, application/x-ms-xbap, */*
Accept-Language: en-gb
User-Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; InfoPath.3)
Accept-Encoding: gzip, deflate
Host: willy.pro.br
Cache-Control: max-age=259200
Connection: keep-alive

HTTP/1.1 200 OK
Date: Wed, 12 Apr 2017 18:16:51 GMT
Content-Type: application/octet-stream
Connection: keep-alive
Keep-Alive: timeout=15
Server: Apache
Cache-Control: no-cache, no-store, max-age=0, must-revalidate
Expires: Tue, 08 Jan 1935 00:00:00 GMT
Pragma: no-cache
Content-Disposition: attachment; filename="6274.exe"
Content-Transfer-Encoding: binary


GET /download1264/ HTTP/1.1
Accept: application/x-ms-application, image/jpeg, application/xaml+xml, image/gif, image/pjpeg, application/x-ms-xbap, */*
Accept-Language: en-GB
User-Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; InfoPath.3)
Accept-Encoding: gzip, deflate
Host: talk-of-the-tyne.co.uk
Cache-Control: max-age=259200
Connection: keep-alive

HTTP/1.1 200 OK
Date: Wed, 12 Apr 2017 18:16:09 GMT
Server: Apache
Cache-Control: no-cache, no-store, max-age=0, must-revalidate
Expires: Tue, 08 Jan 1935 00:00:00 GMT
Pragma: no-cache
Content-Disposition: attachment; filename="5198.exe"
Content-Transfer-Encoding: binary
Vary: User-Agent
X-Powered-By: PleskLin
MS-Author-Via: DAV
Keep-Alive: timeout=15, max=100
Connection: Keep-Alive
Content-Type: application/octet-stream


GET /lDu52756eeJMW/ HTTP/1.1
Accept: */*
Accept-Encoding: gzip, deflate
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; InfoPath.3)
Host: matchpointpro.com
Cache-Control: max-age=259200
Connection: keep-alive

HTTP/1.1 200 OK
Server: nginx
Date: Wed, 12 Apr 2017 18:11:09 GMT
Content-Type: application/octet-stream
Connection: keep-alive
Keep-Alive: timeout=15
Cache-Control: no-cache, no-store, max-age=0, must-revalidate
Expires: Tue, 08 Jan 1935 00:00:00 GMT
Pragma: no-cache
Content-Disposition: attachment; filename="5345.exe"
Content-Transfer-Encoding: binary
ngpass_ngall: 1

 

Still in the process of building my Analysis Lab, so this is not quite how I would like to post, but some information is better than none.

EQGRP-Auction-Files Password Released.

Published 09/04/2017 / by jeff / Leave a Comment
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The ShadowBrokers have released the password for the EQGRP files.

There is a repository on github that has downloaded and starting to delve deeper into the contents of these files.

https://github.com/x0rz/EQGRP

These list various exploits, I’ve not had the chance to look through much of these yet, but over the next few days, I will be having a read and a play around with these files to see what things can be learnt from them.

The password for the original file leak is – CrDj”(;Va.*NdlnzB9M?@K2)#>deB7mN

Currently you can download the files from here.

Now that these have been released, the patches for many of these exploits should follow – if not so already patched.

 

Decimal IP Campaign

Published 04/04/2017 / by jeff / Leave a Comment
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Saw this article today and its quite interesting.

https://blog.malwarebytes.com/cybercrime/2017/03/websites-compromised-decimal-ip-campaign/

A quick search of the string “1760468715” shows there are quite a few websites that have been compromised.

This is quite a clever but old technique that is referred to as Dotless IP’s.  A google search will find quite a few results, with several posts from around 15 or so years ago.

In order to work out the IP address the value represents you can perform a fairly straight forward calculation.

If you had the IP address 172.16.4.8

You can calculate this as follows

172 * 16777216 = 2885681152
16 * 65536 = 1048576
4 * 256 = 1024
8 * 1 = 8

Add the bold figures up.

2886730760

So if you were to enter this address in your browser http://2886730760

It would attempt to take you to 172.16.4.8

Just another way of hiding in plain sight.