Analysis

  • max time kernel
    161s
  • max time network
    143s
  • platform
    windows10_x64
  • resource
    win10-en-20211014
  • submitted
    20-10-2021 09:41

General

  • Target

    BuildS.exe

  • Size

    53KB

  • MD5

    d0feecd8202129bb9c19823a04cd93ce

  • SHA1

    631b2e3c26dfa53778d881e592cc9e499e7f98bb

  • SHA256

    0dc4a2e2f49b2a6265a3c011d186a6f79ca8356d49d1c687465a5d994b6db38a

  • SHA512

    03676f15ee822f550e2dc5e979d205ce0f154d2e1062a7d8257931ca945c6f536de913f28f4abc0a399a0b1bacd380cbff3f26d0ec597c0d7593f349b121e097

Malware Config

Extracted

Path

C:\how_to_back_files.html

Ransom Note
<html> <style type="text/css"> body { background-color: #f5f5f5; } h1, h3{ text-align: center; text-transform: uppercase; font-weight: normal; } /*---*/ .tabs1{ display: block; margin: auto; } .tabs1 .head{ text-align: center; float: top; padding: 0px; text-transform: uppercase; font-weight: normal; display: block; background: #81bef7; color: #DF0101; font-size: 30px; } .tabs1 .identi { font-size: 10px; text-align: center; float: top; padding: 15px; display: block; background: #81bef7; color: #DFDFDF; } .tabs .content { background: #f5f5f5; /*text-align: center;*/ color: #000000; padding: 25px 15px; font-size: 15px; font-weight: 400; line-height: 20px; } .tabs .content a { color: #df0130; font-size: 23px; font-style: italic; text-decoration: none; line-height: 35px; } .tabs .content .text{ padding: 25px; line-height: 1.2; } </style> <body> <div class="tabs1"> <div class="head" ><b>Your personal ID:</b></div> <div class="identi"> <span style="width:1000px; color: #ffffff; font-size: 10px;">����������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span> <br> <!-- !!! dont changing this !!! --> </div> </div> <!-- --> <div class="tabs"> <!--tab--> <div class="tab"> <div id="tab-content1" class="content"> <div class="text"> <!--text data --> <b>/!\ YOUR COMPANY NETWORK HAS BEEN PENETRATED /!\</b><br> <b>All your important files have been encrypted!</b><br><br> <hr> Your files are safe! Only modified. (RSA+AES)<br><br> ANY ATTEMPT TO RESTORE YOUR FILES WITH THIRD-PARTY SOFTWARE<br> WILL PERMANENTLY CORRUPT IT.<br> DO NOT MODIFY ENCRYPTED FILES.<br> DO NOT RENAME ENCRYPTED FILES.<br><br> No software available on internet can help you. We are the only ones able to<br> solve your problem.<br><br> We gathered highly confidential/personal data. These data are currently stored on<br> a private server. This server will be immediately destroyed after your payment.<br> If you decide to not pay, we will release your data to public or re-seller.<br> So you can expect your data to be publicly available in the near future..<br><br> We only seek money and our goal is not to damage your reputation or prevent<br> your business from running.<br><br> You will can send us 2-3 non-important files and we will decrypt it for free<br> to prove we are able to give your files back.<br><br> <!--text data --> <hr> <b>Contact us for price and get decryption software.</b><br><br> <a>qd7pcafncosqfqu3ha6fcx4h6sr7tzwagzpcdcnytiw3b6varaeqv5yd.onion</a><br> * Note that this server is available via Tor browser only<br><br> Follow the instructions to open the link:<br> 1. Type the addres "https://www.torproject.org" in your Internet browser. It opens the Tor site.<br> 2. Press "Download Tor", then press "Download Tor Browser Bundle", install and run it.<br> 3. Now you have Tor browser. In the Tor Browser open <a>qd7pcafncosqfqu3ha6fcx4h6sr7tzwagzpcdcnytiw3b6varaeqv5yd.onion </a><br> 4. Start a chat and follow the further instructions. <br><br> <hr> <b>If you can not use the above link, use the email:</b><br> <a href="[email protected] ">[email protected] </a> <br><a href="[email protected]">[email protected]</a> <br> <b>* To contact us, create a new free email account on the site:</b> <a href="https://protonmail.com">protonmail.com<br> <hr> <b> IF YOU DON'T CONTACT US WITHIN 72 HOURS, PRICE WILL BE HIGHER.</b><br> </div> </div> </div> <!--tab--> <!--text data --> </div> </div> <!--tab--> </div> </div> </body> </html> �����������

Signatures

  • Modifies extensions of user files 11 IoCs

    Ransomware generally changes the extension on encrypted files.

  • Reads user/profile data of web browsers 2 TTPs

    Infostealers often target stored browser data, which can include saved credentials etc.

  • Drops desktop.ini file(s) 26 IoCs
  • Drops file in Program Files directory 64 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\BuildS.exe
    "C:\Users\Admin\AppData\Local\Temp\BuildS.exe"
    1⤵
    • Modifies extensions of user files
    • Drops desktop.ini file(s)
    • Drops file in Program Files directory
    PID:2476

Network

MITRE ATT&CK Enterprise v6

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Downloads