rule win_elise_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.elise."
        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.elise"
        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 = { 6a01 8bd3 e8???????? 0fb6c0 8b4f44 8b573c 33f6 }
            // n = 7, score = 400
            //   6a01                 | push                1
            //   8bd3                 | mov                 edx, ebx
            //   e8????????           |                     
            //   0fb6c0               | movzx               eax, al
            //   8b4f44               | mov                 ecx, dword ptr [edi + 0x44]
            //   8b573c               | mov                 edx, dword ptr [edi + 0x3c]
            //   33f6                 | xor                 esi, esi

        $sequence_1 = { 33c9 888f00010000 888f01010000 8bf7 }
            // n = 4, score = 400
            //   33c9                 | xor                 ecx, ecx
            //   888f00010000         | mov                 byte ptr [edi + 0x100], cl
            //   888f01010000         | mov                 byte ptr [edi + 0x101], cl
            //   8bf7                 | mov                 esi, edi

        $sequence_2 = { ff4c2410 8d7c7e01 75cf 8bc7 5f }
            // n = 5, score = 400
            //   ff4c2410             | dec                 dword ptr [esp + 0x10]
            //   8d7c7e01             | lea                 edi, [esi + edi*2 + 1]
            //   75cf                 | jne                 0xffffffd1
            //   8bc7                 | mov                 eax, edi
            //   5f                   | pop                 edi

        $sequence_3 = { c20400 55 8bec 51 8309ff 8b4108 53 }
            // n = 7, score = 400
            //   c20400               | ret                 4
            //   55                   | push                ebp
            //   8bec                 | mov                 ebp, esp
            //   51                   | push                ecx
            //   8309ff               | or                  dword ptr [ecx], 0xffffffff
            //   8b4108               | mov                 eax, dword ptr [ecx + 8]
            //   53                   | push                ebx

        $sequence_4 = { 0bc5 8bcb 8dbe06050000 f3ab }
            // n = 4, score = 400
            //   0bc5                 | or                  eax, ebp
            //   8bcb                 | mov                 ecx, ebx
            //   8dbe06050000         | lea                 edi, [esi + 0x506]
            //   f3ab                 | rep stosd           dword ptr es:[edi], eax

        $sequence_5 = { 03c6 50 e8???????? 03c6 4f }
            // n = 5, score = 400
            //   03c6                 | add                 eax, esi
            //   50                   | push                eax
            //   e8????????           |                     
            //   03c6                 | add                 eax, esi
            //   4f                   | dec                 edi

        $sequence_6 = { 735a 3b4614 7606 807e1c00 744f 43 33c9 }
            // n = 7, score = 400
            //   735a                 | jae                 0x5c
            //   3b4614               | cmp                 eax, dword ptr [esi + 0x14]
            //   7606                 | jbe                 8
            //   807e1c00             | cmp                 byte ptr [esi + 0x1c], 0
            //   744f                 | je                  0x51
            //   43                   | inc                 ebx
            //   33c9                 | xor                 ecx, ecx

        $sequence_7 = { 8b690c 56 57 85ed 7440 8b4118 83787800 }
            // n = 7, score = 400
            //   8b690c               | mov                 ebp, dword ptr [ecx + 0xc]
            //   56                   | push                esi
            //   57                   | push                edi
            //   85ed                 | test                ebp, ebp
            //   7440                 | je                  0x42
            //   8b4118               | mov                 eax, dword ptr [ecx + 0x18]
            //   83787800             | cmp                 dword ptr [eax + 0x78], 0

        $sequence_8 = { e8???????? 837df804 7306 8365f800 eb10 }
            // n = 5, score = 400
            //   e8????????           |                     
            //   837df804             | cmp                 dword ptr [ebp - 8], 4
            //   7306                 | jae                 8
            //   8365f800             | and                 dword ptr [ebp - 8], 0
            //   eb10                 | jmp                 0x12

        $sequence_9 = { 7908 4b 81cb00ffffff 43 0fb6fb 8a1c07 8b7df0 }
            // n = 7, score = 300
            //   7908                 | jns                 0xa
            //   4b                   | dec                 ebx
            //   81cb00ffffff         | or                  ebx, 0xffffff00
            //   43                   | inc                 ebx
            //   0fb6fb               | movzx               edi, bl
            //   8a1c07               | mov                 bl, byte ptr [edi + eax]
            //   8b7df0               | mov                 edi, dword ptr [ebp - 0x10]

        $sequence_10 = { ff45f8 8b7df8 3b7d0c 0f8c7bffffff 5f }
            // n = 5, score = 300
            //   ff45f8               | inc                 dword ptr [ebp - 8]
            //   8b7df8               | mov                 edi, dword ptr [ebp - 8]
            //   3b7d0c               | cmp                 edi, dword ptr [ebp + 0xc]
            //   0f8c7bffffff         | jl                  0xffffff81
            //   5f                   | pop                 edi

        $sequence_11 = { 85f6 7507 33c0 e9???????? 833d????????00 }
            // n = 5, score = 300
            //   85f6                 | test                esi, esi
            //   7507                 | jne                 9
            //   33c0                 | xor                 eax, eax
            //   e9????????           |                     
            //   833d????????00       |                     

        $sequence_12 = { 42 0fb6fa 8a1c07 881c06 8a5dff 881c07 8b5df8 }
            // n = 7, score = 300
            //   42                   | inc                 edx
            //   0fb6fa               | movzx               edi, dl
            //   8a1c07               | mov                 bl, byte ptr [edi + eax]
            //   881c06               | mov                 byte ptr [esi + eax], bl
            //   8a5dff               | mov                 bl, byte ptr [ebp - 1]
            //   881c07               | mov                 byte ptr [edi + eax], bl
            //   8b5df8               | mov                 ebx, dword ptr [ebp - 8]

        $sequence_13 = { 0bd6 40 83f80e 72e7 }
            // n = 4, score = 300
            //   0bd6                 | or                  edx, esi
            //   40                   | inc                 eax
            //   83f80e               | cmp                 eax, 0xe
            //   72e7                 | jb                  0xffffffe9

        $sequence_14 = { 83ec10 8365f800 837d0c00 8a8800010000 }
            // n = 4, score = 300
            //   83ec10               | sub                 esp, 0x10
            //   8365f800             | and                 dword ptr [ebp - 8], 0
            //   837d0c00             | cmp                 dword ptr [ebp + 0xc], 0
            //   8a8800010000         | mov                 cl, byte ptr [eax + 0x100]

        $sequence_15 = { ff75ec 1155f4 53 e8???????? 8bd8 }
            // n = 5, score = 300
            //   ff75ec               | push                dword ptr [ebp - 0x14]
            //   1155f4               | adc                 dword ptr [ebp - 0xc], edx
            //   53                   | push                ebx
            //   e8????????           |                     
            //   8bd8                 | mov                 ebx, eax

    condition:
        7 of them and filesize < 204800
}

rule win_elise_w0 {
    meta:
        author = "ThreatConnect Intelligence Research Team - Wes Hurd"
        license = "Usage of this signature is subject to the ThreatConnect Terms of Service, which are incorporated herein by reference."
        source = "https://github.com/mattulm/sfiles_yara/blob/master/malware/Elise.yar"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.elise"
        malpedia_version = "20170517"
        malpedia_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"
    strings:
        $0E = "\\000ELISEA"
        $D = "~DF37382D8F2E.tmp" nocase wide ascii
        $SE = "SetElise.pdb" wide ascii
        $xpage = "/%x/page_%02d%02d%02d%02d.html" wide ascii
    condition:
        any of them
}