rule win_karma_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.karma."
        info = "autogenerated rule brought to you by yara-signator"
        tool = "yara-signator v0.6.0"
        signator_config = "callsandjumps;datarefs;binvalue"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.karma"
        malpedia_rule_date = "20260422"
        malpedia_hash = "a182e35da64e6d71cb55f125c4d4225196523f14"
        malpedia_version = "20260504"
        malpedia_license = "CC BY-SA 4.0"
        malpedia_sharing = "TLP:WHITE"

    /* DISCLAIMER
     * The strings used in this rule have been automatically selected from the
     * disassembly of memory dumps and unpacked files, using YARA-Signator.
     * The code and documentation is published here:
     * https://github.com/fxb-cocacoding/yara-signator
     * As Malpedia is used as data source, please note that for a given
     * number of families, only single samples are documented.
     * This likely impacts the degree of generalization these rules will offer.
     * Take the described generation method also into consideration when you
     * apply the rules in your use cases and assign them confidence levels.
     */


    strings:
        $sequence_0 = { 83c010 83f820 7ce5 33c0 }
            // n = 4, score = 100
            //   83c010               | add                 eax, 0x10
            //   83f820               | cmp                 eax, 0x20
            //   7ce5                 | jl                  0xffffffe7
            //   33c0                 | xor                 eax, eax

        $sequence_1 = { 0f8570ffffff 8b45f8 8b4df4 33d2 5f 66891471 8b4df0 }
            // n = 7, score = 100
            //   0f8570ffffff         | jne                 0xffffff76
            //   8b45f8               | mov                 eax, dword ptr [ebp - 8]
            //   8b4df4               | mov                 ecx, dword ptr [ebp - 0xc]
            //   33d2                 | xor                 edx, edx
            //   5f                   | pop                 edi
            //   66891471             | mov                 word ptr [ecx + esi*2], dx
            //   8b4df0               | mov                 ecx, dword ptr [ebp - 0x10]

        $sequence_2 = { d1f8 40 8d1400 660f1f440000 0fb70411 8d4902 668901 }
            // n = 7, score = 100
            //   d1f8                 | sar                 eax, 1
            //   40                   | inc                 eax
            //   8d1400               | lea                 edx, [eax + eax]
            //   660f1f440000         | nop                 word ptr [eax + eax]
            //   0fb70411             | movzx               eax, word ptr [ecx + edx]
            //   8d4902               | lea                 ecx, [ecx + 2]
            //   668901               | mov                 word ptr [ecx], ax

        $sequence_3 = { e8???????? 8b4e04 e8???????? eb16 e8???????? 33d2 b9???????? }
            // n = 7, score = 100
            //   e8????????           |                     
            //   8b4e04               | mov                 ecx, dword ptr [esi + 4]
            //   e8????????           |                     
            //   eb16                 | jmp                 0x18
            //   e8????????           |                     
            //   33d2                 | xor                 edx, edx
            //   b9????????           |                     

        $sequence_4 = { 0f1f4000 8b51fc 8d49fc 85d2 }
            // n = 4, score = 100
            //   0f1f4000             | nop                 dword ptr [eax]
            //   8b51fc               | mov                 edx, dword ptr [ecx - 4]
            //   8d49fc               | lea                 ecx, [ecx - 4]
            //   85d2                 | test                edx, edx

        $sequence_5 = { 83c102 8bf0 6685c0 75e3 85d2 }
            // n = 5, score = 100
            //   83c102               | add                 ecx, 2
            //   8bf0                 | mov                 esi, eax
            //   6685c0               | test                ax, ax
            //   75e3                 | jne                 0xffffffe5
            //   85d2                 | test                edx, edx

        $sequence_6 = { 668908 83c002 8a4dfd c645fe00 c645ff01 eb1f 807dff00 }
            // n = 7, score = 100
            //   668908               | mov                 word ptr [eax], cx
            //   83c002               | add                 eax, 2
            //   8a4dfd               | mov                 cl, byte ptr [ebp - 3]
            //   c645fe00             | mov                 byte ptr [ebp - 2], 0
            //   c645ff01             | mov                 byte ptr [ebp - 1], 1
            //   eb1f                 | jmp                 0x21
            //   807dff00             | cmp                 byte ptr [ebp - 1], 0

        $sequence_7 = { 0f1f00 0f104405dc 0f1088b8404000 660fefc8 0f114c05dc }
            // n = 5, score = 100
            //   0f1f00               | nop                 dword ptr [eax]
            //   0f104405dc           | movups              xmm0, xmmword ptr [ebp + eax - 0x24]
            //   0f1088b8404000       | movups              xmm1, xmmword ptr [eax + 0x4040b8]
            //   660fefc8             | pxor                xmm1, xmm0
            //   0f114c05dc           | movups              xmmword ptr [ebp + eax - 0x24], xmm1

        $sequence_8 = { 0fb702 8d4902 668901 8d5202 6685c0 75ef 33c9 }
            // n = 7, score = 100
            //   0fb702               | movzx               eax, word ptr [edx]
            //   8d4902               | lea                 ecx, [ecx + 2]
            //   668901               | mov                 word ptr [ecx], ax
            //   8d5202               | lea                 edx, [edx + 2]
            //   6685c0               | test                ax, ax
            //   75ef                 | jne                 0xfffffff1
            //   33c9                 | xor                 ecx, ecx

        $sequence_9 = { 7469 8b01 8b4904 56 33f6 8945ec 894df0 }
            // n = 7, score = 100
            //   7469                 | je                  0x6b
            //   8b01                 | mov                 eax, dword ptr [ecx]
            //   8b4904               | mov                 ecx, dword ptr [ecx + 4]
            //   56                   | push                esi
            //   33f6                 | xor                 esi, esi
            //   8945ec               | mov                 dword ptr [ebp - 0x14], eax
            //   894df0               | mov                 dword ptr [ebp - 0x10], ecx

    condition:
        7 of them and filesize < 49208
}

import "pe"

rule win_karma_w0 {
    meta:
        author = "Blackberry Threat Research Team"
        description = "Detects Karma Ransomware 2021"
        date = "2021-10"
        license = "This Yara rule is provided under the Apache License 2.0 (https://www.apache.org/licenses/LICENSE-2.0) and open to any user or organization, as long as you use it under this license and ensure originator credit in any derivative to The BlackBerry Research & Intelligence Team"
        source = "https://blogs.blackberry.com/en/2021/11/threat-thursday-karma-ransomware"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.karma"
        malpedia_rule_date = "20211108"
        malpedia_hash = ""
        malpedia_version = "20211108"
        malpedia_license = "Apache License 2.0"
        malpedia_sharing = "TLP:WHITE"
 
    strings:
        $s1 = "WW91ciBuZXR3b3JrIGhhcyBiZWVuIGJyZWFjaGVkIGJ5IEthcm1hIHJhbnNvbXdhcmUgZ3JvdXAu" ascii wide
        $x2 = "crypt32.dll" nocase
        $x3 = "KARMA" ascii wide
        $x4 = "Sleep" nocase                            

    condition:
        //PE File
        uint16(0) == 0x5a4d and
        //Base64 Karma Note
        all of ($s*) and
        //All Strings
        all of ($x*)
}