Trojan.Ransom.WannaCryptor

Classification

Malware

Trojan

W32

WCryr,WannaCry.[variant],Wanna Decryptor,Trojan:W32/WannaCry.[variant],Trojan.Ransom.WannaCryptor.[variant],Win32.Trojan-Ransom.WannaCry.[variant],Trojan:W32/WannaCryptor.[variant]!Deepguard

Summary

Trojan.Ransom.WannaCryptor identifies the WannaCry ransomware, which encrypts the affected device and demands payment of a ransom to restore normal use.

WannaCry is also known as Wanna Decryptor and WCryr.

Detections

F-Secure security products detect all known variants of this threat with a combination of generic detections and family-specific detections, including (but not limited to):

  • Trojan.Ransom.WannaCryptor.H
  • Trojan:W32/WannaCryptor.A!Deepguard
  • Gen:Variant.Ransom.WannaCryptor.1
  • Gen:Trojan.Heur.RP.JtW@aePsbmpi
  • Suspicious:W32/Malware.51e4307093!Online

Please ensure your F-Secure security product is up-to-date with the latest detection database updates and has Deepguard turned on for maximum coverage.

Removal

Automatic action

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

Exploit prevention

The WannaCry ransomware attack uses known vulnerabilities in the Windows operating system to spread and infect machines. Microsoft has already released a fix for this issue in its March 2017 Security Bulletin. It is strongly recommended that users and administrators ensure that all their systems have received the patch:

Users on systems using versions such as Windows XP that no longer have mainstream support should refer to Microsoft's blogpost offering more details of emergency security patches they have released in response to this issue:

Suspect a file is incorrectly detected (a False Positive)?

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest detection database updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    NOTE If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note You need administrative rights to change the settings.

Find out more

Knowledge Base

Find the latest advice in our Community Knowledge Base.

User Guide

See the user guide for your product on the Help Center.

Contact Support

Chat with or call an expert for help.

Submit a sample

Submit a file or URL for further analysis.

Technical Details

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:

Infection

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.

Encryption

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

Ransom demand

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: