Earlier today, our products detected and successfully blocked a large number of ransomware attacks around the world. In these attacks, data is encrypted with the extension “.WCRY” added to the filenames.
Our analysis indicates the attack, dubbed “WannaCry”, is initiated through an SMBv2 remote code execution in Microsoft Windows. This exploit (codenamed “EternalBlue”) has been made available on the internet through the Shadowbrokers dump on April 14th, 2017 and patched by Microsoft on March 14.
Unfortunately, it appears that many organizations have not yet installed the patch.
A few hours ago, Spain’s Computer Emergency Response Team CCN-CERT, posted an alert on their site about a massive ransomware attack affecting several Spanish organizations. The alert recommends the installation of updates in the Microsoft March 2017 Security Bulletin as a means of stopping the spread of the attack.
The National Health Service (NHS) in the U.K. also issued an alert and confirmed infections at 16 medical institutions. We have confirmed additional infections in several additional countries, including Russia, Ukraine, and India.
It’s important to understand that while unpatched Windows computers exposing their SMB services can be remotely attacked with the “EternalBlue” exploit and infected by the WannaCry ransomware, the lack of existence of this vulnerability doesn’t really prevent the ransomware component from working. Nevertheless, the presence of this vulnerability appears to be the most significant factor that caused the outbreak.
CCN-CERT alert (in Spanish)
Analysis of the attack
Currently, we have recorded more than 45,000 attacks of the WannaCry ransomware in 74 countries around the world, mostly in Russia. It’s important to note that our visibility may be limited and incomplete and the range of targets and victims is likely much, much higher.
Geographical target distribution according to our telemetry for the first few hours of the attack
The malware used in the attacks encrypts the files and also drops and executes a decryptor tool. The request for $600 in Bitcoin is displayed along with the wallet. It’s interesting that the initial request in this sample is for $600 USD, as the first five payments to that wallet is approximately $300 USD. It suggests that the group is increasing the ransom demands.
The tool was designed to address users of multiple countries, with translated messages in different languages.
Language list that the malware supports
Note that the “payment will be raised” after a specific countdown, along with another display raising urgency to pay up, threatening that the user will completely lose their files after the set timeout. Not all ransomware provides this timer countdown.
To make sure that the user doesn’t miss the warning, the tool changes the user’s wallpaper with instructions on how to find the decryptor tool dropped by the malware.
An image used to replace user’s wallpaper
Malware samples contain no reference to any specific culture or codepage other than universal English and Latin codepage CP1252. The files contain version info stolen from random Microsoft Windows 7 system tools:
Properties of malware files used by WannaCry
For convenient bitcoin payments, the malware directs to a page with a QR code at btcfrog, which links to their main bitcoin wallet 13AM4VW2dhxYgXeQepoHkHSQuy6NgaEb94. Image metadata does not provide any additional info:
One of the Bitcoin wallets used by the attackers: 13AM4VW2dhxYgXeQepoHkHSQuy6NgaEb94
One of the attacker wallets received 0.88 BTC during the last hours
Another Bitcoin wallets included in the attackers’ “readme.txt” from the samples are:
115p7UMMngoj1pMvkpHijcRdfJNXj6LrLn – 0.32 BTC
12t9YDPgwueZ9NyMgw519p7AA8isjr6SMw – 0.16 BTC
For command and control, the malware extracts and uses Tor service executable with all necessary dependencies to access the Tor network:
A list of dropped files related to Tor service
In terms of targeted files, the ransomware encrypts files with the following extensions:
.der, .pfx, .key, .crt, .csr, .p12, .pem, .odt, .ott, .sxw, .stw, .uot, .3ds, .max, .3dm, .ods, .ots, .sxc, .stc, .dif, .slk, .wb2, .odp, .otp, .sxd, .std, .uop, .odg, .otg, .sxm, .mml, .lay, .lay6, .asc, .sqlite3, .sqlitedb, .sql, .accdb, .mdb, .dbf, .odb, .frm, .myd, .myi, .ibd, .mdf, .ldf, .sln, .suo, .cpp, .pas, .asm, .cmd, .bat, .ps1, .vbs, .dip, .dch, .sch, .brd, .jsp, .php, .asp, .java, .jar, .class, .mp3, .wav, .swf, .fla, .wmv, .mpg, .vob, .mpeg, .asf, .avi, .mov, .mp4, .3gp, .mkv, .3g2, .flv, .wma, .mid, .m3u, .m4u, .djvu, .svg, .psd, .nef, .tiff, .tif, .cgm, .raw, .gif, .png, .bmp, .jpg, .jpeg, .vcd, .iso, .backup, .zip, .rar, .tgz, .tar, .bak, .tbk, .bz2, .PAQ, .ARC, .aes, .gpg, .vmx, .vmdk, .vdi, .sldm, .sldx, .sti, .sxi, .602, .hwp, .snt, .onetoc2, .dwg, .pdf, .wk1, .wks, .123, .rtf, .csv, .txt, .vsdx, .vsd, .edb, .eml, .msg, .ost, .pst, .potm, .potx, .ppam, .ppsx, .ppsm, .pps, .pot, .pptm, .pptx, .ppt, .xltm, .xltx, .xlc, .xlm, .xlt, .xlw, .xlsb, .xlsm, .xlsx, .xls, .dotx, .dotm, .dot, .docm, .docb, .docx, .doc
The file extensions that the malware is targeting contain certain clusters of formats including:
- Commonly used office file extensions (.ppt, .doc, .docx, .xlsx, .sxi).
- Less common and nation-specific office formats (.sxw, .odt, .hwp).
- Archives, media files (.zip, .rar, .tar, .bz2, .mp4, .mkv)
- Emails and email databases (.eml, .msg, .ost, .pst, .edb).
- Database files (.sql, .accdb, .mdb, .dbf, .odb, .myd).
- Developers’ sourcecode and project files (.php, .java, .cpp, .pas, .asm).
- Encryption keys and certificates (.key, .pfx, .pem, .p12, .csr, .gpg, .aes).
- Graphic designers, artists and photographers files (.vsd, .odg, .raw, .nef, .svg, .psd).
- Virtual machine files (.vmx, .vmdk, .vdi).
The WannaCry dropper drops multiple “user manuals” on different languages:
Bulgarian, Chinese (simplified), Chinese (traditional), Croatian, Czech, Danish, Dutch, English, Filipino, Finnish, French, German, Greek, Indonesian, Italian, Japanese, Korean, Latvian, Norwegian, Polish, Portuguese, Romanian, Russian, Slovak, Spanish, Swedish, Turkish, Vietnamese
The example of a “user manual” in English:
What Happened to My Computer?
Your important files are encrypted.
Many of your documents, photos, videos, databases and other files are no longer accessible because they have been encrypted. Maybe you are busy looking for a way to
recover your files, but do not waste your time. Nobody can recover your files without our decryption service.
Can I Recover My Files?
Sure. We guarantee that you can recover all your files safely and easily. But you have not so enough time.
You can decrypt some of your files for free. Try now by clicking http://ift.tt/2pt7GAA Source: https://securelist.com