rule win_appleseed_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-05-16"
        version = "1"
        description = "Detects win.appleseed."
        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.appleseed"
        malpedia_rule_date = "20220513"
        malpedia_hash = "7f4b2229e6ae614d86d74917f6d5b41890e62a26"
        malpedia_version = "20220516"
        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 = { 488d93c80f0000 488bcb e8???????? 448b8374af0100 8b9370af0100 488d0d18040200 e8???????? }
            // n = 7, score = 100
            //   488d93c80f0000       | inc                 esp
            //   488bcb               | mov                 eax, ebx
            //   e8????????           |                     
            //   448b8374af0100       | dec                 ecx
            //   8b9370af0100         | mov                 edx, edi
            //   488d0d18040200       | dec                 eax
            //   e8????????           |                     

        $sequence_1 = { 48833d????????00 7463 488d15b1160200 488d4db8 }
            // n = 4, score = 100
            //   48833d????????00     |                     
            //   7463                 | inc                 esp
            //   488d15b1160200       | mov                 eax, dword ptr [ebx + 0x1af74]
            //   488d4db8             | mov                 edx, dword ptr [ebx + 0x1af70]

        $sequence_2 = { 57 4156 488d6c24c0 4881ec40010000 48c7442460feffffff 488b05???????? 4833c4 }
            // n = 7, score = 100
            //   57                   | dec                 eax
            //   4156                 | lea                 ecx, [esp + 0x44]
            //   488d6c24c0           | ret                 
            //   4881ec40010000       | inc                 eax
            //   48c7442460feffffff     | push    ebx
            //   488b05????????       |                     
            //   4833c4               | dec                 eax

        $sequence_3 = { 488d1565e80100 488bc8 e8???????? 84c0 }
            // n = 4, score = 100
            //   488d1565e80100       | dec                 eax
            //   488bc8               | mov                 dword ptr [esp + 0x80], esi
            //   e8????????           |                     
            //   84c0                 | dec                 eax

        $sequence_4 = { 4833c4 4889442470 488bd9 c744243000000000 }
            // n = 4, score = 100
            //   4833c4               | lea                 edx, [0x21e8c]
            //   4889442470           | dec                 eax
            //   488bd9               | lea                 ecx, [ebp - 0x48]
            //   c744243000000000     | inc                 ecx

        $sequence_5 = { 488bf7 4c8bff 49c1ff05 4c8d2d86bb0100 83e61f 486bf658 4b8b44fd00 }
            // n = 7, score = 100
            //   488bf7               | dec                 eax
            //   4c8bff               | lea                 ecx, [ebp - 0x48]
            //   49c1ff05             | dec                 eax
            //   4c8d2d86bb0100       | mov                 dword ptr [ebp - 0x30], 0xf
            //   83e61f               | dec                 eax
            //   486bf658             | mov                 dword ptr [ebp - 0x38], ebx
            //   4b8b44fd00           | mov                 byte ptr [ebp - 0x48], 0

        $sequence_6 = { 488d6c24d9 4881eca0000000 48c745e7feffffff 48899c24f8000000 488b05???????? }
            // n = 5, score = 100
            //   488d6c24d9           | lea                 ecx, [ebp + 0xd81]
            //   4881eca0000000       | dec                 eax
            //   48c745e7feffffff     | lea                 edx, [ebx + 0x1f0]
            //   48899c24f8000000     | xor                 edx, edx
            //   488b05????????       |                     

        $sequence_7 = { 488d15c1610200 41b804010000 ff15???????? ffcb 7505 e8???????? b801000000 }
            // n = 7, score = 100
            //   488d15c1610200       | mov                 dword ptr [ebx + 0x20], ebp
            //   41b804010000         | dec                 eax
            //   ff15????????         |                     
            //   ffcb                 | xor                 eax, esp
            //   7505                 | dec                 eax
            //   e8????????           |                     
            //   b801000000           | mov                 dword ptr [esp + 0x50], eax

        $sequence_8 = { 48c1f805 83e11f 488d15e7cc0100 488b04c2 486bc958 c644080800 85db }
            // n = 7, score = 100
            //   48c1f805             | mov                 eax, edx
            //   83e11f               | dec                 eax
            //   488d15e7cc0100       | mov                 edx, ecx
            //   488b04c2             | dec                 eax
            //   486bc958             | lea                 ecx, [0x4dc9]
            //   c644080800           | test                eax, eax
            //   85db                 | dec                 ebp

        $sequence_9 = { 4885c0 7512 4c3bf3 7305 83c8ff eb08 8bc7 }
            // n = 7, score = 100
            //   4885c0               | dec                 esp
            //   7512                 | lea                 eax, [0x23a08]
            //   4c3bf3               | dec                 eax
            //   7305                 | mov                 edx, edi
            //   83c8ff               | dec                 eax
            //   eb08                 | lea                 ecx, [esp + 0x40]
            //   8bc7                 | dec                 eax

    condition:
        7 of them and filesize < 497664
}

rule win_appleseed_w0 {
    meta:
        author = "KrCERT/CC Profound Analysis Team"
        date = "2020-12-4"
        info = "Operation MUZABI"
        hash = "43cc6d190238e851d33066cbe9be9ac8"
        hash = "fd10bd6013aabadbcb9edb8a23ba7331"
        hash = "16231e2e8991c60a42f293e0c33ff801"
        hash = "89fff6645013008cda57f88639b92990"
        hash = "030e2f992cbc4e61f0d5c994779caf3b"
        hash = "3620c22671641fbf32cf496b118b85f6"
        hash = "4876fc88c361743a1220a7b161f8f06f"
        hash = "94b8a0e4356d0202dc61046e3d8bdfe0"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.appleseed"
        malpedia_rule_date = "20201015"
        malpedia_version = "20201015"
        malpedia_license = "CC NC-BY-SA 4.0"
        malpedia_sharing = "TLP:WHITE"

    strings:
        $appleseed_str1 = {0f 8? ?? (00|01) 00 00 [0-1] 83 f? 20 0f 8? (01|00) 00 00}
        $appleseed_str2 = {88 45 [0-15] 0f b6 44 ?? 01}
        $appleseed_str3 = {83 f? 10 [0-5] 83 e? 10}
        $appleseed_key1 = {89 04 ?9 [0-6] ff 34 ?? e8 [10-16] 89 0c 98 8b ?? 0c [0-3] ff 34 98}
        $appleseed_key2 = {83 f? 10 [0-10] 32 4c 05 ?? ?? 88 4c ?? 0f}
        $appleseed_key3 = {89 04 ?9 49 83 ?? 04 48 ?? ?? 10 8b 0c a8 e8 [0-10] 48 8b ?? ?8}
        $seed_str1 = {44 0f b6 44 3d c0 45 32 c7 44 32 45 d4}
        $seed_str2 = {0f b6 44 3? ?? [0-25] 83 c4 0c}
        $seed_str3 = {32 45 c? ?? ?? ?? 32 45 e?}

    condition: 
            uint16(0) == 0x5a4d
        and
            filesize < 400KB
        and
            (2 of ($appleseed_str*))
        and
            (1 of ($seed_str*))
        and
            (1 of ($appleseed_key*))
}