rule win_appleseed_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2021-06-10"
        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 = "20210604"
        malpedia_hash = "be09d5d71e77373c0f538068be31a2ad4c69cfbd"
        malpedia_version = "20210616"
        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 = { 488d45e0 4983c8ff 49ffc0 42803c0000 75f6 488d55e0 488d4c2430 }
            // n = 7, score = 100
            //   488d45e0             | mov                 dword ptr [ebp + 0x158], esi
            //   4983c8ff             | mov                 byte ptr [ebp + 0x148], 0
            //   49ffc0               | dec                 eax
            //   42803c0000           | lea                 ecx, dword ptr [ebp - 0x40]
            //   75f6                 | test                eax, eax
            //   488d55e0             | jne                 0x14f2
            //   488d4c2430           | dec                 eax

        $sequence_1 = { 4533f6 418bfe 488b4118 488b10 48c785e00000000f000000 4c89b5d8000000 4088bdc8000000 }
            // n = 7, score = 100
            //   4533f6               | dec                 eax
            //   418bfe               | xor                 eax, esp
            //   488b4118             | dec                 eax
            //   488b10               | mov                 dword ptr [ebp + 0x47], eax
            //   48c785e00000000f000000     | xor    edi, edi
            //   4c89b5d8000000       | mov                 dword ptr [ebp + 0x3f], edi
            //   4088bdc8000000       | dec                 eax

        $sequence_2 = { 33f6 48897568 40887558 403832 7505 448bc6 eb11 }
            // n = 7, score = 100
            //   33f6                 | inc                 ebp
            //   48897568             | xor                 eax, eax
            //   40887558             | dec                 eax
            //   403832               | mov                 edx, eax
            //   7505                 | dec                 eax
            //   448bc6               | lea                 ecx, dword ptr [ebp + 0x30]
            //   eb11                 | dec                 eax

        $sequence_3 = { 48833d????????00 0f842c160000 48c745d00f000000 48895dc8 c645b800 41b836000000 488d15ac1c0200 }
            // n = 7, score = 100
            //   48833d????????00     |                     
            //   0f842c160000         | mov                 dword ptr [ebp + 0x30], eax
            //   48c745d00f000000     | inc                 ebp
            //   48895dc8             | mov                 esi, eax
            //   c645b800             | dec                 eax
            //   41b836000000         | mov                 edi, edx
            //   488d15ac1c0200       | dec                 eax

        $sequence_4 = { 4881ec80000000 48c745b8feffffff 488b05???????? 4833c4 488945f0 498bf0 488bda }
            // n = 7, score = 100
            //   4881ec80000000       | jb                  0x537
            //   48c745b8feffffff     | dec                 eax
            //   488b05????????       |                     
            //   4833c4               | mov                 ecx, dword ptr [ebp + 0x58]
            //   488945f0             | dec                 eax
            //   498bf0               | mov                 eax, dword ptr [eax]
            //   488bda               | dec                 eax

        $sequence_5 = { 72ed 48833d????????00 741f 488d0de2dc0100 }
            // n = 4, score = 100
            //   72ed                 | lea                 ecx, dword ptr [0x258da]
            //   48833d????????00     |                     
            //   741f                 | int3                
            //   488d0de2dc0100       | dec                 eax

        $sequence_6 = { 41b8ff030000 488d4d21 e8???????? 448bc6 488d15da3b0200 488d4d20 e8???????? }
            // n = 7, score = 100
            //   41b8ff030000         | dec                 eax
            //   488d4d21             | mov                 dword ptr [ebp - 0x48], ecx
            //   e8????????           |                     
            //   448bc6               | inc                 ebp
            //   488d15da3b0200       | xor                 ebp, ebp
            //   488d4d20             | inc                 ecx
            //   e8????????           |                     

        $sequence_7 = { 90 488d4db8 e8???????? 48833d????????00 0f84df060000 488d151d180200 488d4db8 }
            // n = 7, score = 100
            //   90                   | lea                 edx, dword ptr [ebp + 0x10]
            //   488d4db8             | dec                 eax
            //   e8????????           |                     
            //   48833d????????00     |                     
            //   0f84df060000         | lea                 ecx, dword ptr [esp + 0x20]
            //   488d151d180200       | mov                 byte ptr [esp + 0x20], 0
            //   488d4db8             | dec                 ecx

        $sequence_8 = { 7208 498b0f e8???????? 49c747180f000000 49897710 41c60700 49837d1810 }
            // n = 7, score = 100
            //   7208                 | mov                 ebx, edi
            //   498b0f               | dec                 eax
            //   e8????????           |                     
            //   49c747180f000000     | mov                 esi, edi
            //   49897710             | dec                 eax
            //   41c60700             | sar                 esi, 5
            //   49837d1810           | dec                 esp

        $sequence_9 = { 4c8d05df770000 418d5216 e8???????? 85c0 0f8544090000 b805000000 }
            // n = 6, score = 100
            //   4c8d05df770000       | dec                 eax
            //   418d5216             | lea                 edx, dword ptr [0x1c18d]
            //   e8????????           |                     
            //   85c0                 | dec                 eax
            //   0f8544090000         | lea                 ecx, dword ptr [esp + 0x40]
            //   b805000000           | mov                 byte ptr [esp + 0x40], 0

    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*))
}