SYMBOLCOMMON_NAMEaka. SYNONYMS
win.yayih (Back to overview)

yayih

aka: bbsinfo, aumlib

There is no description at this point.

References
2013-08-12FireEyeNart Villeneuve, Ned Moran
@online{villeneuve:20130812:survival:4544f24, author = {Nart Villeneuve and Ned Moran}, title = {{Survival of the Fittest: New York Times Attackers Evolve Quickly}}, date = {2013-08-12}, organization = {FireEye}, url = {https://www.fireeye.com/blog/threat-research/2013/08/survival-of-the-fittest-new-york-times-attackers-evolve-quickly.html}, language = {English}, urldate = {2019-12-20} } Survival of the Fittest: New York Times Attackers Evolve Quickly
yayih
Yara Rules
[TLP:WHITE] win_yayih_auto (20230125 | Detects win.yayih.)
rule win_yayih_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-01-25"
        version = "1"
        description = "Detects win.yayih."
        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.yayih"
        malpedia_rule_date = "20230124"
        malpedia_hash = "2ee0eebba83dce3d019a90519f2f972c0fcf9686"
        malpedia_version = "20230125"
        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 = { 8d4580 50 68???????? e8???????? 8b35???????? 83c40c }
            // n = 6, score = 100
            //   8d4580               | lea                 eax, [ebp - 0x80]
            //   50                   | push                eax
            //   68????????           |                     
            //   e8????????           |                     
            //   8b35????????         |                     
            //   83c40c               | add                 esp, 0xc

        $sequence_1 = { 8d85e0f9ffff 50 e8???????? 8d45b8 50 8d85e0f9ffff }
            // n = 6, score = 100
            //   8d85e0f9ffff         | lea                 eax, [ebp - 0x620]
            //   50                   | push                eax
            //   e8????????           |                     
            //   8d45b8               | lea                 eax, [ebp - 0x48]
            //   50                   | push                eax
            //   8d85e0f9ffff         | lea                 eax, [ebp - 0x620]

        $sequence_2 = { 85c0 56 7509 56 56 6a01 }
            // n = 6, score = 100
            //   85c0                 | test                eax, eax
            //   56                   | push                esi
            //   7509                 | jne                 0xb
            //   56                   | push                esi
            //   56                   | push                esi
            //   6a01                 | push                1

        $sequence_3 = { 0f844b010000 8d45ac 8b3d???????? 50 8d45ec 50 8d45f0 }
            // n = 7, score = 100
            //   0f844b010000         | je                  0x151
            //   8d45ac               | lea                 eax, [ebp - 0x54]
            //   8b3d????????         |                     
            //   50                   | push                eax
            //   8d45ec               | lea                 eax, [ebp - 0x14]
            //   50                   | push                eax
            //   8d45f0               | lea                 eax, [ebp - 0x10]

        $sequence_4 = { 59 33c0 8dbde9faffff 889de8faffff f3ab }
            // n = 5, score = 100
            //   59                   | pop                 ecx
            //   33c0                 | xor                 eax, eax
            //   8dbde9faffff         | lea                 edi, [ebp - 0x517]
            //   889de8faffff         | mov                 byte ptr [ebp - 0x518], bl
            //   f3ab                 | rep stosd           dword ptr es:[edi], eax

        $sequence_5 = { 83650800 8b550c 8d78ff 59 85ff }
            // n = 5, score = 100
            //   83650800             | and                 dword ptr [ebp + 8], 0
            //   8b550c               | mov                 edx, dword ptr [ebp + 0xc]
            //   8d78ff               | lea                 edi, [eax - 1]
            //   59                   | pop                 ecx
            //   85ff                 | test                edi, edi

        $sequence_6 = { 740c 39b57cffffff 0f856e0e0000 817dc8c8000000 0f853f010000 6a44 }
            // n = 6, score = 100
            //   740c                 | je                  0xe
            //   39b57cffffff         | cmp                 dword ptr [ebp - 0x84], esi
            //   0f856e0e0000         | jne                 0xe74
            //   817dc8c8000000       | cmp                 dword ptr [ebp - 0x38], 0xc8
            //   0f853f010000         | jne                 0x145
            //   6a44                 | push                0x44

        $sequence_7 = { 81ff00200000 c7450800200000 7303 897d08 ff7508 }
            // n = 5, score = 100
            //   81ff00200000         | cmp                 edi, 0x2000
            //   c7450800200000       | mov                 dword ptr [ebp + 8], 0x2000
            //   7303                 | jae                 5
            //   897d08               | mov                 dword ptr [ebp + 8], edi
            //   ff7508               | push                dword ptr [ebp + 8]

        $sequence_8 = { c745fce0930400 ff15???????? 53 53 53 53 }
            // n = 6, score = 100
            //   c745fce0930400       | mov                 dword ptr [ebp - 4], 0x493e0
            //   ff15????????         |                     
            //   53                   | push                ebx
            //   53                   | push                ebx
            //   53                   | push                ebx
            //   53                   | push                ebx

        $sequence_9 = { 8bec 83ec14 8065ec00 56 57 }
            // n = 5, score = 100
            //   8bec                 | mov                 ebp, esp
            //   83ec14               | sub                 esp, 0x14
            //   8065ec00             | and                 byte ptr [ebp - 0x14], 0
            //   56                   | push                esi
            //   57                   | push                edi

    condition:
        7 of them and filesize < 57344
}
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