rule win_karma_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        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 = "20260916"
        malpedia_hash = "53a643781c18e08f4a50949af60172d837a0b6f6"
        malpedia_version = "20260917"
        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 = { 56 57 8d0c00 0fb70411 8d5202 668902 }
            // n = 6, score = 100
            //   56                   | push                esi
            //   57                   | push                edi
            //   8d0c00               | lea                 ecx, [eax + eax]
            //   0fb70411             | movzx               eax, word ptr [ecx + edx]
            //   8d5202               | lea                 edx, [edx + 2]
            //   668902               | mov                 word ptr [edx], ax

        $sequence_1 = { 8d8df4fdffff e8???????? ba???????? 8d8df4fdffff e8???????? 8d95f4fdffff b9???????? }
            // n = 7, score = 100
            //   8d8df4fdffff         | lea                 ecx, [ebp - 0x20c]
            //   e8????????           |                     
            //   ba????????           |                     
            //   8d8df4fdffff         | lea                 ecx, [ebp - 0x20c]
            //   e8????????           |                     
            //   8d95f4fdffff         | lea                 edx, [ebp - 0x20c]
            //   b9????????           |                     

        $sequence_2 = { 83c104 83f808 72f2 0f843e010000 8d7e20 33c0 90 }
            // n = 7, score = 100
            //   83c104               | add                 ecx, 4
            //   83f808               | cmp                 eax, 8
            //   72f2                 | jb                  0xfffffff4
            //   0f843e010000         | je                  0x144
            //   8d7e20               | lea                 edi, [esi + 0x20]
            //   33c0                 | xor                 eax, eax
            //   90                   | nop                 

        $sequence_3 = { 0f1148f0 83e901 75e7 8d55e0 }
            // n = 4, score = 100
            //   0f1148f0             | movups              xmmword ptr [eax - 0x10], xmm1
            //   83e901               | sub                 ecx, 1
            //   75e7                 | jne                 0xffffffe9
            //   8d55e0               | lea                 edx, [ebp - 0x20]

        $sequence_4 = { 0f1f00 8d4010 0f104c18f0 0f1040f0 }
            // n = 4, score = 100
            //   0f1f00               | nop                 dword ptr [eax]
            //   8d4010               | lea                 eax, [eax + 0x10]
            //   0f104c18f0           | movups              xmm1, xmmword ptr [eax + ebx - 0x10]
            //   0f1040f0             | movups              xmm0, xmmword ptr [eax - 0x10]

        $sequence_5 = { 7443 0fb71406 2bd1 7509 83c002 66391406 }
            // n = 6, score = 100
            //   7443                 | je                  0x45
            //   0fb71406             | movzx               edx, word ptr [esi + eax]
            //   2bd1                 | sub                 edx, ecx
            //   7509                 | jne                 0xb
            //   83c002               | add                 eax, 2
            //   66391406             | cmp                 word ptr [esi + eax], dx

        $sequence_6 = { e9???????? 7f0c 8b442418 3bf8 0f8224ffffff }
            // n = 5, score = 100
            //   e9????????           |                     
            //   7f0c                 | jg                  0xe
            //   8b442418             | mov                 eax, dword ptr [esp + 0x18]
            //   3bf8                 | cmp                 edi, eax
            //   0f8224ffffff         | jb                  0xffffff2a

        $sequence_7 = { 8d55e0 57 8bca e8???????? 8d4de0 83c404 }
            // n = 6, score = 100
            //   8d55e0               | lea                 edx, [ebp - 0x20]
            //   57                   | push                edi
            //   8bca                 | mov                 ecx, edx
            //   e8????????           |                     
            //   8d4de0               | lea                 ecx, [ebp - 0x20]
            //   83c404               | add                 esp, 4

        $sequence_8 = { 83fe01 751d 8bc6 0f1f440000 837c85e000 7506 }
            // n = 6, score = 100
            //   83fe01               | cmp                 esi, 1
            //   751d                 | jne                 0x1f
            //   8bc6                 | mov                 eax, esi
            //   0f1f440000           | nop                 dword ptr [eax + eax]
            //   837c85e000           | cmp                 dword ptr [ebp + eax*4 - 0x20], 0
            //   7506                 | jne                 8

        $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*)
}