Home / malware

PDF

Trojan.Ransomcrypt.P

First posted on 06 January 2015.
Source: Symantec

Aliases :

There are no other names known for Trojan.Ransomcrypt.P.

Explanation :

Once executed, the Trojan creates the following files:
%UserProfile%\Application Data\WinCL\wincl.exe%UserProfile%\Application Data\WinCL\wincl.jpg%UserProfile%\Application Data\WinCL\enc_files.txt%UserProfile%\Application Data\WinCL\last_chance.txt
The Trojan then creates the following registry entry so that it runs every time Windows starts:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run\"wincl" = "%UserProfile%\Application Data\WinCL\wincl.exe"
Next, the Trojan creates the following registry subkeys:
HKEY_CURRENT_USER\Software\VB and VBA Program Settings\CLOCK\SDataHKEY_CURRENT_USER\Software\VB and VBA Program Settings\CLOCK\EData
The Trojan then attempts to encrypt files with any of the following extensions:
.3fr.accdb.ai.arw.bay.cdr.cer.cr2.crt.crw.dbf.dcr.der.dng.doc.docm.docx.dwg.dxf.dxg.eps.erf.indd.jpe.jpg.kdc.mdb.mdf.mef.mrw.nef.nrw.odb.odm.odp.ods.odt.orf.p12.p7b.p7c.pdd.pef.pem.pfx.ppt.pptm.pptx.psd.pst.ptx.r3d.raf.raw.rtf.rw2.rwl.srf.srw.wb2.wpd.wps.xlk.xls.xlsb.xlsm.xlsx
The Trojan then deletes any shadow copies the operating system may have made of the encrypted files.

Next, the Trojan contacts the following legitimate website in order to find out the current value of a bitcoin:
https://blockchain.info
The Trojan then connects to the following remote location:
[http://]invisioncorp.com.au
It may then download an update of itself from the following remote location:
[http://]invisioncorp.com.au/scripts/wl/cl.[REMOVED]
Next, the Trojan uses the following image file to change the desktop wallpaper:
%UserProfile%\Application Data\WinCL\wincl.jpg
The Trojan then displays a message with the following text:

"Your Personal Files Are Encrypted!

Your personal files encryption *produced on this computer: photos, videos, /documents, etc. Encryption was produced using a public key RSA-2048 generated for this computer.
To decrypt files you need to obtain the single copy of the private key, which will allow to decrypt the files, located n a secret server on the Internet; the server will destroy the key after a time specified in this window. After that, nobody and never will be able to restore files...

To obtain the private key for this computer, which will automatically decrypt files, you need to pay [calculated] bitcoin (~300 USD). You can easily delete this software, but know that without it, you will never be able to get your original files back.
For more information on how to buy and send bitcoins, click "Pay with Bitcoin".
To open a list of encoded files, click "Show files".
Disable your antivirus to prevent the removal of this software.
Do not delete this list, it will be used for decryption. And do not move your files."

Last update 06 January 2015

 

TOP