WannaCry came to public notice in a major outbreak that was first reported on Friday, 13 May 2017:
For more information about this incident, see:
The WannaCry ransomware is spread by a dropper component that exploits known vulnerabilities in Windows to drop the ransomware binary onto a vulnerable machine. If the dropper is successful in exploiting an Internet-facing machine, it can also use vulnerabilities in Windows SMB Server to infect other computers on the same local area network.
As part of its attack, the WannaCry dropper component uses an exploit known as EternalBlue, which was first publicized in the data allegedly stolen from the US's National Security Agency (NSA) and released by hacking group The Shadow Brokers.
The vulnerabilities used to spread WannaCry have already been fixed by Microsoft in March 2017 with the MS17-010 patch; systems that have not yet received the fix however remain vulnerable. It is strongly recommended that users and administrators ensure that all their systems have received the MS17-010 patch to prevent the WannaCry ransomware from gaining entry to their machines.
The WannaCry ransomware encrypts all files stored on the affected machine. The encryption uses the AES 128-bit encryption algorithms, which are extremely difficult to break.
It encrypts the following file types: .doc, .docx, .docb, .docm, .dot, .dotm, .dotx, .xls, .xlsx, .xlsm, .xlsb, .xlw, .xlt, .xlm, .xlc, .xltx, .xltm, .ppt, .pptx, .pptm, .pot, .pps, .ppsm, .ppsx, .ppam, .potx, .potm, .pst, .ost, .msg, .eml, .edb, .vsd, .vsdx, .txt, .csv, .rtf, .123, .wks, .wk1, .pdf, .dwg, .onetoc2, .snt, .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, .jpeg, .jpg, .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
Once the files have been encrypted, WannaCry displays a ransom demand for up to $300 in Bitcoin. A video and screenshots of the ransomware in action can be seen in the following post on F-Secure's Safe and Savvy blog: