Decrypt Ransomware-Locked System Files

My core system files have been encrypted and rendered unusable after a ransomware strike. I already know the exact strain responsible and can supply the ransom note, extension pattern, sample encrypted files, and any logs you may need... (Budget: ₹12500 - ₹37500 INR, Jobs: Data Protection, Digital Forensics, Encryption, Forensic Consulting, Network Security, Penetration Testing, Reverse Engineering, System Administration)