SYMBOLCOMMON_NAMEaka. SYNONYMS
win.excalibur (Back to overview)

Excalibur

aka: Sabresac, Saber

There is no description at this point.

References
2016-10-18CylanceCylance Threat Research Team
@online{team:20161018:digitally:f1b3290, author = {Cylance Threat Research Team}, title = {{Digitally Signed Malware Targeting Gaming Companies}}, date = {2016-10-18}, organization = {Cylance}, url = {https://blog.cylance.com/digitally-signed-malware-targeting-gaming-companies}, language = {English}, urldate = {2020-01-06} } Digitally Signed Malware Targeting Gaming Companies
Excalibur
Yara Rules
[TLP:WHITE] win_excalibur_auto (20220808 | Detects win.excalibur.)
rule win_excalibur_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-08-05"
        version = "1"
        description = "Detects win.excalibur."
        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.excalibur"
        malpedia_rule_date = "20220805"
        malpedia_hash = "6ec06c64bcfdbeda64eff021c766b4ce34542b71"
        malpedia_version = "20220808"
        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 = { 837df408 720b ff75e0 e8???????? 83c404 8b4df8 5f }
            // n = 7, score = 100
            //   837df408             | cmp                 dword ptr [ebp - 0xc], 8
            //   720b                 | jb                  0xd
            //   ff75e0               | push                dword ptr [ebp - 0x20]
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   8b4df8               | mov                 ecx, dword ptr [ebp - 8]
            //   5f                   | pop                 edi

        $sequence_1 = { 3bff 0f854a020000 8b45a0 3bc8 0f853f020000 85ff 7513 }
            // n = 7, score = 100
            //   3bff                 | cmp                 edi, edi
            //   0f854a020000         | jne                 0x250
            //   8b45a0               | mov                 eax, dword ptr [ebp - 0x60]
            //   3bc8                 | cmp                 ecx, eax
            //   0f853f020000         | jne                 0x245
            //   85ff                 | test                edi, edi
            //   7513                 | jne                 0x15

        $sequence_2 = { 83e21f 8b0c8dc0324400 c1e206 89040a 8bc3 e9???????? 53 }
            // n = 7, score = 100
            //   83e21f               | and                 edx, 0x1f
            //   8b0c8dc0324400       | mov                 ecx, dword ptr [ecx*4 + 0x4432c0]
            //   c1e206               | shl                 edx, 6
            //   89040a               | mov                 dword ptr [edx + ecx], eax
            //   8bc3                 | mov                 eax, ebx
            //   e9????????           |                     
            //   53                   | push                ebx

        $sequence_3 = { 8b06 eb02 8bc6 0fbe0c38 8b02 8d0480 8d40e8 }
            // n = 7, score = 100
            //   8b06                 | mov                 eax, dword ptr [esi]
            //   eb02                 | jmp                 4
            //   8bc6                 | mov                 eax, esi
            //   0fbe0c38             | movsx               ecx, byte ptr [eax + edi]
            //   8b02                 | mov                 eax, dword ptr [edx]
            //   8d0480               | lea                 eax, [eax + eax*4]
            //   8d40e8               | lea                 eax, [eax - 0x18]

        $sequence_4 = { c7465c08574300 83660800 33ff 47 897e14 897e70 6a43 }
            // n = 7, score = 100
            //   c7465c08574300       | mov                 dword ptr [esi + 0x5c], 0x435708
            //   83660800             | and                 dword ptr [esi + 8], 0
            //   33ff                 | xor                 edi, edi
            //   47                   | inc                 edi
            //   897e14               | mov                 dword ptr [esi + 0x14], edi
            //   897e70               | mov                 dword ptr [esi + 0x70], edi
            //   6a43                 | push                0x43

        $sequence_5 = { 3bc3 0f82f9fcffff 8bd8 8b45c0 48 2bd8 8b45e0 }
            // n = 7, score = 100
            //   3bc3                 | cmp                 eax, ebx
            //   0f82f9fcffff         | jb                  0xfffffcff
            //   8bd8                 | mov                 ebx, eax
            //   8b45c0               | mov                 eax, dword ptr [ebp - 0x40]
            //   48                   | dec                 eax
            //   2bd8                 | sub                 ebx, eax
            //   8b45e0               | mov                 eax, dword ptr [ebp - 0x20]

        $sequence_6 = { 8b07 40 8a48ff 8907 84c9 7514 ff750c }
            // n = 7, score = 100
            //   8b07                 | mov                 eax, dword ptr [edi]
            //   40                   | inc                 eax
            //   8a48ff               | mov                 cl, byte ptr [eax - 1]
            //   8907                 | mov                 dword ptr [edi], eax
            //   84c9                 | test                cl, cl
            //   7514                 | jne                 0x16
            //   ff750c               | push                dword ptr [ebp + 0xc]

        $sequence_7 = { 3bf3 0f8dd7000000 8b4da4 8d642400 8b9560ffffff 8bbd4cffffff 83fa10 }
            // n = 7, score = 100
            //   3bf3                 | cmp                 esi, ebx
            //   0f8dd7000000         | jge                 0xdd
            //   8b4da4               | mov                 ecx, dword ptr [ebp - 0x5c]
            //   8d642400             | lea                 esp, [esp]
            //   8b9560ffffff         | mov                 edx, dword ptr [ebp - 0xa0]
            //   8bbd4cffffff         | mov                 edi, dword ptr [ebp - 0xb4]
            //   83fa10               | cmp                 edx, 0x10

        $sequence_8 = { 5d c20800 8b8568fdffff 85c0 74e1 8d4dec 51 }
            // n = 7, score = 100
            //   5d                   | pop                 ebp
            //   c20800               | ret                 8
            //   8b8568fdffff         | mov                 eax, dword ptr [ebp - 0x298]
            //   85c0                 | test                eax, eax
            //   74e1                 | je                  0xffffffe3
            //   8d4dec               | lea                 ecx, [ebp - 0x14]
            //   51                   | push                ecx

        $sequence_9 = { 741a 8d8568fdffff 50 68ff000f00 56 ff15???????? }
            // n = 6, score = 100
            //   741a                 | je                  0x1c
            //   8d8568fdffff         | lea                 eax, [ebp - 0x298]
            //   50                   | push                eax
            //   68ff000f00           | push                0xf00ff
            //   56                   | push                esi
            //   ff15????????         |                     

    condition:
        7 of them and filesize < 1253376
}
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