rule win_elise_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        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 = "20230705"
        malpedia_hash = "42d0574f4405bd7d2b154d321d345acb18834a41"
        malpedia_version = "20230715"
        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 = { 7475 8b4d08 0b4d0c 745f 3b4648 735a }
            // n = 6, score = 400
            //   7475                 | je                  0x77
            //   8b4d08               | mov                 ecx, dword ptr [ebp + 8]
            //   0b4d0c               | or                  ecx, dword ptr [ebp + 0xc]
            //   745f                 | je                  0x61
            //   3b4648               | cmp                 eax, dword ptr [esi + 0x48]
            //   735a                 | jae                 0x5c

        $sequence_1 = { 83400801 6a04 5e 11580c 8955fc }
            // n = 5, score = 400
            //   83400801             | add                 dword ptr [eax + 8], 1
            //   6a04                 | push                4
            //   5e                   | pop                 esi
            //   11580c               | adc                 dword ptr [eax + 0xc], ebx
            //   8955fc               | mov                 dword ptr [ebp - 4], edx

        $sequence_2 = { 8bfe e8???????? 8945f4 83f8ff }
            // n = 4, score = 400
            //   8bfe                 | mov                 edi, esi
            //   e8????????           |                     
            //   8945f4               | mov                 dword ptr [ebp - 0xc], eax
            //   83f8ff               | cmp                 eax, -1

        $sequence_3 = { 8d46c0 8945f0 83f804 0f8299000000 33db }
            // n = 5, score = 400
            //   8d46c0               | lea                 eax, [esi - 0x40]
            //   8945f0               | mov                 dword ptr [ebp - 0x10], eax
            //   83f804               | cmp                 eax, 4
            //   0f8299000000         | jb                  0x9f
            //   33db                 | xor                 ebx, ebx

        $sequence_4 = { 7cf5 33c9 888f00010000 888f01010000 8bf7 }
            // n = 5, score = 400
            //   7cf5                 | jl                  0xfffffff7
            //   33c9                 | xor                 ecx, ecx
            //   888f00010000         | mov                 byte ptr [edi + 0x100], cl
            //   888f01010000         | mov                 byte ptr [edi + 0x101], cl
            //   8bf7                 | mov                 esi, edi

        $sequence_5 = { 8d041f ff75e4 50 e8???????? 033d???????? }
            // n = 5, score = 400
            //   8d041f               | lea                 eax, [edi + ebx]
            //   ff75e4               | push                dword ptr [ebp - 0x1c]
            //   50                   | push                eax
            //   e8????????           |                     
            //   033d????????         |                     

        $sequence_6 = { 395d08 7307 8b5d08 c645ff01 895de4 85db }
            // n = 6, score = 400
            //   395d08               | cmp                 dword ptr [ebp + 8], ebx
            //   7307                 | jae                 9
            //   8b5d08               | mov                 ebx, dword ptr [ebp + 8]
            //   c645ff01             | mov                 byte ptr [ebp - 1], 1
            //   895de4               | mov                 dword ptr [ebp - 0x1c], ebx
            //   85db                 | test                ebx, ebx

        $sequence_7 = { 034e3c b800030000 d3e0 53 }
            // n = 4, score = 400
            //   034e3c               | add                 ecx, dword ptr [esi + 0x3c]
            //   b800030000           | mov                 eax, 0x300
            //   d3e0                 | shl                 eax, cl
            //   53                   | push                ebx

        $sequence_8 = { 8945dc 33c0 8d7dec ab ab }
            // n = 5, score = 400
            //   8945dc               | mov                 dword ptr [ebp - 0x24], eax
            //   33c0                 | xor                 eax, eax
            //   8d7dec               | lea                 edi, [ebp - 0x14]
            //   ab                   | stosd               dword ptr es:[edi], eax
            //   ab                   | stosd               dword ptr es:[edi], eax

        $sequence_9 = { e9???????? 833d????????00 7405 e8???????? 83c8ff }
            // n = 5, score = 300
            //   e9????????           |                     
            //   833d????????00       |                     
            //   7405                 | je                  7
            //   e8????????           |                     
            //   83c8ff               | or                  eax, 0xffffffff

        $sequence_10 = { 33c2 eb02 d1e8 4e 75f1 }
            // n = 5, score = 300
            //   33c2                 | xor                 eax, edx
            //   eb02                 | jmp                 4
            //   d1e8                 | shr                 eax, 1
            //   4e                   | dec                 esi
            //   75f1                 | jne                 0xfffffff3

        $sequence_11 = { 8a9001010000 0f8e93000000 53 56 57 0fb6f1 }
            // n = 6, score = 300
            //   8a9001010000         | mov                 dl, byte ptr [eax + 0x101]
            //   0f8e93000000         | jle                 0x99
            //   53                   | push                ebx
            //   56                   | push                esi
            //   57                   | push                edi
            //   0fb6f1               | movzx               esi, cl

        $sequence_12 = { 33c9 6a08 8bc1 5e a801 7406 }
            // n = 6, score = 300
            //   33c9                 | xor                 ecx, ecx
            //   6a08                 | push                8
            //   8bc1                 | mov                 eax, ecx
            //   5e                   | pop                 esi
            //   a801                 | test                al, 1
            //   7406                 | je                  8

        $sequence_13 = { 59 8b45f0 8b55f4 5f 5e 5b }
            // n = 6, score = 300
            //   59                   | pop                 ecx
            //   8b45f0               | mov                 eax, dword ptr [ebp - 0x10]
            //   8b55f4               | mov                 edx, dword ptr [ebp - 0xc]
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi
            //   5b                   | pop                 ebx

        $sequence_14 = { 8d4e01 81e1ff000080 7908 49 81c900ffffff 41 }
            // n = 6, score = 300
            //   8d4e01               | lea                 ecx, [esi + 1]
            //   81e1ff000080         | and                 ecx, 0x800000ff
            //   7908                 | jns                 0xa
            //   49                   | dec                 ecx
            //   81c900ffffff         | or                  ecx, 0xffffff00
            //   41                   | inc                 ecx

        $sequence_15 = { 301f ff45f8 8b7df8 3b7d0c 0f8c7bffffff }
            // n = 5, score = 300
            //   301f                 | xor                 byte ptr [edi], bl
            //   ff45f8               | inc                 dword ptr [ebp - 8]
            //   8b7df8               | mov                 edi, dword ptr [ebp - 8]
            //   3b7d0c               | cmp                 edi, dword ptr [ebp + 0xc]
            //   0f8c7bffffff         | jl                  0xffffff81

    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
}