What is Arrow ransomware
CrySiS or Dharma ransomware encrypts files on the infected computer and upends one of several extensions to encrypted files. The newest variant uses .arrow (.[marat20@cock.li].arrow, .[blammo@cock.li].arrow, .[java2018@tuta io].arrow, .[helprestore@cock.li].arrow) extension. Right now there is no free decryptor, and there may never be one. First two variants of CrySiS (.crysis and .dharma) had free decryptors released eventually but none of the later variants (.wallet, .arena, .cesar, .java) have so far. If your files have been encrypted by CrySiS and you don’t have back-ups, your best bet would be to back up encrypted files in case the free decryption tool is released in the future, and meanwhile try some methods of file recovery that may be able to restore at least some of the files.