SYMBOLCOMMON_NAMEaka. SYNONYMS
win.final1stspy (Back to overview)

Final1stSpy

Actor(s): APT37


There is no description at this point.

References
2018-10-03IntezerJay Rosenberg
@online{rosenberg:20181003:apt37:93a9100, author = {Jay Rosenberg}, title = {{APT37: Final1stspy Reaping the FreeMilk}}, date = {2018-10-03}, organization = {Intezer}, url = {https://www.intezer.com/apt37-final1stspy-reaping-the-freemilk/}, language = {English}, urldate = {2020-01-09} } APT37: Final1stspy Reaping the FreeMilk
Final1stSpy RokRAT
Yara Rules
[TLP:WHITE] win_final1stspy_auto (20220808 | Detects win.final1stspy.)
rule win_final1stspy_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-08-05"
        version = "1"
        description = "Detects win.final1stspy."
        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.final1stspy"
        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 = { 8bf0 8945fc 57 8d7e01 8a06 46 84c0 }
            // n = 7, score = 300
            //   8bf0                 | mov                 esi, eax
            //   8945fc               | mov                 dword ptr [ebp - 4], eax
            //   57                   | push                edi
            //   8d7e01               | lea                 edi, [esi + 1]
            //   8a06                 | mov                 al, byte ptr [esi]
            //   46                   | inc                 esi
            //   84c0                 | test                al, al

        $sequence_1 = { 75f9 2bf7 56 e8???????? 8bc8 83c404 894df8 }
            // n = 7, score = 300
            //   75f9                 | jne                 0xfffffffb
            //   2bf7                 | sub                 esi, edi
            //   56                   | push                esi
            //   e8????????           |                     
            //   8bc8                 | mov                 ecx, eax
            //   83c404               | add                 esp, 4
            //   894df8               | mov                 dword ptr [ebp - 8], ecx

        $sequence_2 = { 8bf8 81e7ff070080 7908 4f 81cf00f8ffff 47 33f6 }
            // n = 7, score = 300
            //   8bf8                 | mov                 edi, eax
            //   81e7ff070080         | and                 edi, 0x800007ff
            //   7908                 | jns                 0xa
            //   4f                   | dec                 edi
            //   81cf00f8ffff         | or                  edi, 0xfffff800
            //   47                   | inc                 edi
            //   33f6                 | xor                 esi, esi

        $sequence_3 = { 5d c3 2d???????? 0f886cffffff 03d0 8bc2 }
            // n = 6, score = 300
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   2d????????           |                     
            //   0f886cffffff         | js                  0xffffff72
            //   03d0                 | add                 edx, eax
            //   8bc2                 | mov                 eax, edx

        $sequence_4 = { 8bc2 c1f810 8806 46 8a1d???????? 83ff02 }
            // n = 6, score = 300
            //   8bc2                 | mov                 eax, edx
            //   c1f810               | sar                 eax, 0x10
            //   8806                 | mov                 byte ptr [esi], al
            //   46                   | inc                 esi
            //   8a1d????????         |                     
            //   83ff02               | cmp                 edi, 2

        $sequence_5 = { 8a1439 80c27a 80f219 881439 41 3bce }
            // n = 6, score = 300
            //   8a1439               | mov                 dl, byte ptr [ecx + edi]
            //   80c27a               | add                 dl, 0x7a
            //   80f219               | xor                 dl, 0x19
            //   881439               | mov                 byte ptr [ecx + edi], dl
            //   41                   | inc                 ecx
            //   3bce                 | cmp                 ecx, esi

        $sequence_6 = { 0f10040f 0f28ca 660ffcc2 660fefc3 }
            // n = 4, score = 300
            //   0f10040f             | movups              xmm0, xmmword ptr [edi + ecx]
            //   0f28ca               | movaps              xmm1, xmm2
            //   660ffcc2             | paddb               xmm0, xmm2
            //   660fefc3             | pxor                xmm0, xmm3

        $sequence_7 = { 56 8bf0 8945fc 57 8d7e01 }
            // n = 5, score = 300
            //   56                   | push                esi
            //   8bf0                 | mov                 esi, eax
            //   8945fc               | mov                 dword ptr [ebp - 4], eax
            //   57                   | push                edi
            //   8d7e01               | lea                 edi, [esi + 1]

        $sequence_8 = { 7410 8a11 8acb 3aca }
            // n = 4, score = 300
            //   7410                 | je                  0x12
            //   8a11                 | mov                 dl, byte ptr [ecx]
            //   8acb                 | mov                 cl, bl
            //   3aca                 | cmp                 cl, dl

        $sequence_9 = { 7908 4f 81cf00f8ffff 47 33f6 85ff 7e0a }
            // n = 7, score = 300
            //   7908                 | jns                 0xa
            //   4f                   | dec                 edi
            //   81cf00f8ffff         | or                  edi, 0xfffff800
            //   47                   | inc                 edi
            //   33f6                 | xor                 esi, esi
            //   85ff                 | test                edi, edi
            //   7e0a                 | jle                 0xc

    condition:
        7 of them and filesize < 557056
}
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