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 (20220411 | Detects win.final1stspy.)
rule win_final1stspy_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-04-08"
        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 = "20220405"
        malpedia_hash = "ecd38294bd47d5589be5cd5490dc8bb4804afc2a"
        malpedia_version = "20220411"
        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 33c9 85f6 7e70 }
            // n = 4, score = 300
            //   8bf0                 | mov                 esi, eax
            //   33c9                 | xor                 ecx, ecx
            //   85f6                 | test                esi, esi
            //   7e70                 | jle                 0x72

        $sequence_1 = { 03d0 8b45fc 8a4803 c1e206 80f93d 7508 }
            // n = 6, score = 300
            //   03d0                 | add                 edx, eax
            //   8b45fc               | mov                 eax, dword ptr [ebp - 4]
            //   8a4803               | mov                 cl, byte ptr [eax + 3]
            //   c1e206               | shl                 edx, 6
            //   80f93d               | cmp                 cl, 0x3d
            //   7508                 | jne                 0xa

        $sequence_2 = { c1e006 8a7201 8ad3 3ad6 7412 8a5101 41 }
            // n = 7, score = 300
            //   c1e006               | shl                 eax, 6
            //   8a7201               | mov                 dh, byte ptr [edx + 1]
            //   8ad3                 | mov                 dl, bl
            //   3ad6                 | cmp                 dl, dh
            //   7412                 | je                  0x14
            //   8a5101               | mov                 dl, byte ptr [ecx + 1]
            //   41                   | inc                 ecx

        $sequence_3 = { 8be5 5d c3 2d???????? 78dc }
            // n = 5, score = 300
            //   8be5                 | mov                 esp, ebp
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   2d????????           |                     
            //   78dc                 | js                  0xffffffde

        $sequence_4 = { 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_5 = { 0f10440f10 660ffcc8 660fefcb 0f114c0f10 83c120 }
            // n = 5, score = 300
            //   0f10440f10           | movups              xmm0, xmmword ptr [edi + ecx + 0x10]
            //   660ffcc8             | paddb               xmm1, xmm0
            //   660fefcb             | pxor                xmm1, xmm3
            //   0f114c0f10           | movups              xmmword ptr [edi + ecx + 0x10], xmm1
            //   83c120               | add                 ecx, 0x20

        $sequence_6 = { 84db 7410 8a11 8acb 3aca 7425 8a4801 }
            // n = 7, score = 300
            //   84db                 | test                bl, bl
            //   7410                 | je                  0x12
            //   8a11                 | mov                 dl, byte ptr [ecx]
            //   8acb                 | mov                 cl, bl
            //   3aca                 | cmp                 cl, dl
            //   7425                 | je                  0x27
            //   8a4801               | mov                 cl, byte ptr [eax + 1]

        $sequence_7 = { 40 0f2815???????? 8bd6 0f281d???????? 2bd0 }
            // n = 5, score = 300
            //   40                   | inc                 eax
            //   0f2815????????       |                     
            //   8bd6                 | mov                 edx, esi
            //   0f281d????????       |                     
            //   2bd0                 | sub                 edx, eax

        $sequence_8 = { 8bec 81ec04080000 a1???????? 33c5 8945fc 56 57 }
            // n = 7, score = 300
            //   8bec                 | mov                 ebp, esp
            //   81ec04080000         | sub                 esp, 0x804
            //   a1????????           |                     
            //   33c5                 | xor                 eax, ebp
            //   8945fc               | mov                 dword ptr [ebp - 4], eax
            //   56                   | push                esi
            //   57                   | push                edi

        $sequence_9 = { 8955f4 56 8bf0 8945fc }
            // n = 4, score = 300
            //   8955f4               | mov                 dword ptr [ebp - 0xc], edx
            //   56                   | push                esi
            //   8bf0                 | mov                 esi, eax
            //   8945fc               | mov                 dword ptr [ebp - 4], eax

    condition:
        7 of them and filesize < 557056
}
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