A new variant of what appears to be BTCWare ransomware is currently targeting victims and appending the .[email]-id-id.payday extension to encrypted files. This family of ransomware targets its victims by hacking into poorly protected remote desktop services and manually installing the ransomware.

Below is a brief summary of changes in this new payday btcware ransomware variant.

What's New in the Payday Ransomware BTCWare Variant

According to Michael Gillespie, the creator of ID-Ransomware, this payday variant uses a new key generation when encrypting files, which cannot be cracked. So unfortunately, there is no way to decrypt payday files for free.

We also have a new BleepingComputer forum account named payday_lock that claims to be the developer making posts in the forums.

Post by the Payday Ransomware Dev
Post by the Payday Ransomware Dev

Other changes include new ransom notes named payday.hta and !! RETURN FILES !!.txt. The main difference in these notes is the contact email, which are Checkzip@india.com & payday@cryptmaster.info. You can see an example of one of the variant's ransom note below.

Payday Ransomware Ransom Note
Payday Ransomware (BTCWare) Ransom Note

The next noticeable change is the extension appended to encrypted files. With this version, when a file is encrypted by the ransomware, it will modify the filename and then append the .[email]-id-id.payday extension to encrypted file's name. For example, the current version will encrypt a file called test.jpg and rename it to test.jpg.[Checkzip@india.com]-id-CE4.payday.

You can see an example of an encrypted folder below.

Folder of Encrypted Payday Files
Folder of Encrypted Payday Files

If any new information or methods to decrypt the files becomes available, we will be sure to update this article.
 

IOCs

File Hashes:

SHA256: 9903c3589f45c8b7cb7bcf2381cdbbdc9b5cdbd8c1d261e2f95e9a0ee6a4d2ff

Filenames associated with the Payday Ransomware Variant:

%AppData%\payday.hta
!! RETURN FILES !!.txt

Payday BTCWare Ransomware Ransom Note Text:

 
All your files have been encrypted!
All your files have been encrypted due to a security problem with your PC. If you want to restore them, write us to the e-mail Checkzip@india.com
You have to pay for decryption in Bitcoins. The price depends on how fast you write to us. After payment we will send you the decryption tool that will decrypt all your files. 
Free decryption as guarantee
Before paying you can send us up to 3 files for free decryption. The total size of files must be less than 1Mb (non archived), and files should not contain valuable information. (databases,backups, large excel sheets, etc.) 
How to obtain Bitcoins
The easiest way to buy bitcoins is LocalBitcoins site. You have to register, click 'Buy bitcoins', and select the seller by payment method and price. 
https://localbitcoins.com/buy_bitcoins 
Also you can find other places to buy Bitcoins and beginners guide here: 
http://www.coindesk.com/information/how-can-i-buy-bitcoins/ 
Attention!
Do not rename encrypted files. 
Do not try to decrypt your data using third party software, it may cause permanent data loss. 
Decryption of your files with the help of third parties may cause increased price (they add their fee to our) or you can become a victim of a scam. 

Emails Associated with the Payday Ransomware:

Checkzip@india.com
payday@cryptmaster.info