rule win_mystic_stealer_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.mystic_stealer."
        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.mystic_stealer"
        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 = { c7460445000000 8b4e04 8d6e1c 83f945 }
            // n = 4, score = 300
            //   c7460445000000       | mov                 dword ptr [esi + 4], 0x45
            //   8b4e04               | mov                 ecx, dword ptr [esi + 4]
            //   8d6e1c               | lea                 ebp, [esi + 0x1c]
            //   83f945               | cmp                 ecx, 0x45

        $sequence_1 = { 234754 83bfb416000000 894748 7452 8b4738 8b4f58 }
            // n = 6, score = 300
            //   234754               | and                 eax, dword ptr [edi + 0x54]
            //   83bfb416000000       | cmp                 dword ptr [edi + 0x16b4], 0
            //   894748               | mov                 dword ptr [edi + 0x48], eax
            //   7452                 | je                  0x54
            //   8b4738               | mov                 eax, dword ptr [edi + 0x38]
            //   8b4f58               | mov                 ecx, dword ptr [edi + 0x58]

        $sequence_2 = { 668bc7 66d3e0 660bc5 0fb7c8 }
            // n = 4, score = 300
            //   668bc7               | mov                 ax, di
            //   66d3e0               | shl                 ax, cl
            //   660bc5               | or                  ax, bp
            //   0fb7c8               | movzx               ecx, ax

        $sequence_3 = { 8b4c241c 83c40c 8b4500 034e14 894e14 }
            // n = 5, score = 300
            //   8b4c241c             | mov                 ecx, dword ptr [esp + 0x1c]
            //   83c40c               | add                 esp, 0xc
            //   8b4500               | mov                 eax, dword ptr [ebp]
            //   034e14               | add                 ecx, dword ptr [esi + 0x14]
            //   894e14               | mov                 dword ptr [esi + 0x14], ecx

        $sequence_4 = { 8d040a 0fb78fb8160000 660bf1 0fb7ce }
            // n = 4, score = 300
            //   8d040a               | lea                 eax, [edx + ecx]
            //   0fb78fb8160000       | movzx               ecx, word ptr [edi + 0x16b8]
            //   660bf1               | or                  si, cx
            //   0fb7ce               | movzx               ecx, si

        $sequence_5 = { 8386bc160000f3 b110 2ac8 66d3ef 0fb7c7 }
            // n = 5, score = 300
            //   8386bc160000f3       | add                 dword ptr [esi + 0x16bc], -0xd
            //   b110                 | mov                 cl, 0x10
            //   2ac8                 | sub                 cl, al
            //   66d3ef               | shr                 di, cl
            //   0fb7c7               | movzx               eax, di

        $sequence_6 = { 80ea03 c6040101 8b8ea0160000 8b8698160000 41 898ea0160000 c6040100 }
            // n = 7, score = 300
            //   80ea03               | sub                 dl, 3
            //   c6040101             | mov                 byte ptr [ecx + eax], 1
            //   8b8ea0160000         | mov                 ecx, dword ptr [esi + 0x16a0]
            //   8b8698160000         | mov                 eax, dword ptr [esi + 0x1698]
            //   41                   | inc                 ecx
            //   898ea0160000         | mov                 dword ptr [esi + 0x16a0], ecx
            //   c6040100             | mov                 byte ptr [ecx + eax], 0

        $sequence_7 = { 59 59 ffd0 8be8 }
            // n = 4, score = 300
            //   59                   | pop                 ecx
            //   59                   | pop                 ecx
            //   ffd0                 | call                eax
            //   8be8                 | mov                 ebp, eax

        $sequence_8 = { 898550140000 898c855c0b0000 33c0 40 6689048b c684295814000000 ff8da8160000 }
            // n = 7, score = 300
            //   898550140000         | mov                 dword ptr [ebp + 0x1450], eax
            //   898c855c0b0000       | mov                 dword ptr [ebp + eax*4 + 0xb5c], ecx
            //   33c0                 | xor                 eax, eax
            //   40                   | inc                 eax
            //   6689048b             | mov                 word ptr [ebx + ecx*4], ax
            //   c684295814000000     | mov                 byte ptr [ecx + ebp + 0x1458], 0
            //   ff8da8160000         | dec                 dword ptr [ebp + 0x16a8]

        $sequence_9 = { 33db 668987b8160000 85ed 0f8ea0000000 }
            // n = 4, score = 300
            //   33db                 | xor                 ebx, ebx
            //   668987b8160000       | mov                 word ptr [edi + 0x16b8], ax
            //   85ed                 | test                ebp, ebp
            //   0f8ea0000000         | jle                 0xa6

    condition:
        7 of them and filesize < 512000
}