rule win_appleseed_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2021-10-07"
        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 = "20211007"
        malpedia_hash = "e5b790e0f888f252d49063a1251ca60ec2832535"
        malpedia_version = "20211008"
        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 = { 4c8945e0 4c894dd8 4983791810 7205 498b09 eb03 498bc9 }
            // n = 7, score = 100
            //   4c8945e0             | mov                 ecx, 1
            //   4c894dd8             | inc                 ebp
            //   4983791810           | xor                 eax, eax
            //   7205                 | dec                 eax
            //   498b09               | mov                 ecx, dword ptr [ebp + 0x40]
            //   eb03                 | mov                 eax, dword ptr [ebp + 0xc4]
            //   498bc9               | cmp                 eax, 3

        $sequence_1 = { 0f8414010000 488d15d2160200 488d4db8 e8???????? 90 488d55d8 488bc8 }
            // n = 7, score = 100
            //   0f8414010000         | dec                 eax
            //   488d15d2160200       | lea                 ecx, dword ptr [ebp + 0x30]
            //   488d4db8             | dec                 eax
            //   e8????????           |                     
            //   90                   | cmp                 dword ptr [ebp + 0x48], 0x10
            //   488d55d8             | dec                 eax
            //   488bc8               | cmovae              ecx, dword ptr [ebp + 0x30]

        $sequence_2 = { 488bfa 488bd9 488d059df80000 488981a0000000 83611000 c7411c01000000 c781c800000001000000 }
            // n = 7, score = 100
            //   488bfa               | dec                 eax
            //   488bd9               | mov                 ecx, eax
            //   488d059df80000       | dec                 eax
            //   488981a0000000       | add                 esp, 0x58
            //   83611000             | dec                 eax
            //   c7411c01000000       | mov                 dword ptr [esp + 0x30], 0xfffffffe
            //   c781c800000001000000     | dec    eax

        $sequence_3 = { 488d151d180200 488d4db8 e8???????? 90 488d55d8 488bc8 e8???????? }
            // n = 7, score = 100
            //   488d151d180200       | mov                 byte ptr [ebp + 0x38], 0
            //   488d4db8             | dec                 ecx
            //   e8????????           |                     
            //   90                   | or                  ecx, 0xffffffff
            //   488d55d8             | inc                 ebp
            //   488bc8               | xor                 eax, eax
            //   e8????????           |                     

        $sequence_4 = { 4885c0 74e7 4883c440 5b c3 488d05ef470100 488d542458 }
            // n = 7, score = 100
            //   4885c0               | dec                 eax
            //   74e7                 | lea                 edx, dword ptr [0x2180f]
            //   4883c440             | dec                 eax
            //   5b                   | lea                 ecx, dword ptr [ebp - 0x48]
            //   c3                   | nop                 
            //   488d05ef470100       | dec                 eax
            //   488d542458           | lea                 edx, dword ptr [ebp - 0x28]

        $sequence_5 = { e8???????? 90 488d542468 488d4c2448 e8???????? 488d4d00 48837d1810 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   90                   | xor                 eax, esp
            //   488d542468           | inc                 eax
            //   488d4c2448           | push                ebp
            //   e8????????           |                     
            //   488d4d00             | push                ebx
            //   48837d1810           | push                esi

        $sequence_6 = { 4c8bc2 3905???????? 89442420 488bd1 7509 488d0dd2480100 eb02 }
            // n = 7, score = 100
            //   4c8bc2               | dec                 eax
            //   3905????????         |                     
            //   89442420             | mov                 ecx, dword ptr [ebp - 0x28]
            //   488bd1               | dec                 eax
            //   7509                 | mov                 eax, esi
            //   488d0dd2480100       | nop                 
            //   eb02                 | dec                 eax

        $sequence_7 = { 48897c2430 c644242000 803a00 7505 4c8bc7 eb11 4983c8ff }
            // n = 7, score = 100
            //   48897c2430           | mov                 ebx, eax
            //   c644242000           | dec                 esp
            //   803a00               | lea                 eax, dword ptr [ebp + 0x140]
            //   7505                 | dec                 eax
            //   4c8bc7               | lea                 edx, dword ptr [0x1bedb]
            //   eb11                 | dec                 eax
            //   4983c8ff             | lea                 ecx, dword ptr [ebp - 0x58]

        $sequence_8 = { ff15???????? 4885c0 0f84a9010000 488bc8 ff15???????? 488d1505a10000 488bcb }
            // n = 7, score = 100
            //   ff15????????         |                     
            //   4885c0               | jb                  0x4b9
            //   0f84a9010000         | dec                 ecx
            //   488bc8               | mov                 ecx, dword ptr [edi]
            //   ff15????????         |                     
            //   488d1505a10000       | dec                 ecx
            //   488bcb               | mov                 dword ptr [edi + 0x18], 0xf

        $sequence_9 = { 498bcd ff15???????? 4c8be0 4885c0 0f84b2000000 }
            // n = 5, score = 100
            //   498bcd               | dec                 eax
            //   ff15????????         |                     
            //   4c8be0               | lea                 ecx, dword ptr [0x9094]
            //   4885c0               | dec                 eax
            //   0f84b2000000         | sub                 esp, 0x48

    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*))
}