import "pe"

rule MAL_Neshta_Generic : HIGHVOL {
   meta:
      description = "Detects Neshta malware"
      author = "Florian Roth (Nextron Systems)"
      reference = "Internal Research"
      date = "2018-01-15"
      modified = "2021-04-14"
      hash1 = "27c67eb1378c2fd054c6649f92ec8ee9bfcb6f790224036c974f6c883c46f586"
      hash1 = "0283c0f02307adc4ee46c0382df4b5d7b4eb80114fbaf5cb7fe5412f027d165e"
      hash2 = "b7f8233dafab45e3abbbb4f3cc76e6860fae8d5337fb0b750ea20058b56b0efb"
      hash3 = "1954e06fc952a5a0328774aaf07c23970efd16834654793076c061dffb09a7eb"
      id = "9a3b8369-7e19-5c21-9eba-0bb81507696a"
   strings:
      $x1 = "the best. Fuck off all the rest."
      $x2 = "! Best regards 2 Tommy Salo. [Nov-2005] yours [Dziadulja Apanas]" fullword ascii

      $s1 = "Neshta" ascii fullword
      $s2 = "Made in Belarus. " ascii fullword

      $op1 = { 85 c0 93 0f 85 62 ff ff ff 5e 5b 89 ec 5d c2 04 }
      $op2 = { e8 e5 f1 ff ff 8b c3 e8 c6 ff ff ff 85 c0 75 0c }
      $op3 = { eb 02 33 db 8b c3 5b c3 53 85 c0 74 15 ff 15 34 }

      $sop1 = { e8 3c 2a ff ff b8 ff ff ff 7f eb 3e 83 7d 0c 00 }
      $sop2 = { 2b c7 50 e8 a4 40 ff ff ff b6 88 }
   condition:
      uint16(0) == 0x5a4d and
      filesize < 3000KB and (
         1 of ($x*) or 
         all of ($s*) or 
         3 of them or 
         pe.imphash() == "9f4693fc0c511135129493f2161d1e86"
      )
}