SYMBOLCOMMON_NAMEaka. SYNONYMS
win.nokoyawa (Back to overview)

Nokoyawa Ransomware


There is no description at this point.

References
2022-08-22MicrosoftMicrosoft
@online{microsoft:20220822:extortion:67c26d4, author = {Microsoft}, title = {{Extortion Economics - Ransomware’s new business model}}, date = {2022-08-22}, organization = {Microsoft}, url = {https://query.prod.cms.rt.microsoft.com/cms/api/am/binary/RE54L7v}, language = {English}, urldate = {2022-08-31} } Extortion Economics - Ransomware’s new business model
BlackCat Conti Hive REvil AgendaCrypt Black Basta BlackCat Brute Ratel C4 Cobalt Strike Conti Hive Mount Locker Nokoyawa Ransomware REvil Ryuk
2022-04-21Sentinel LABSAntonis Terefos
@online{terefos:20220421:nokoyawa:72ae5e2, author = {Antonis Terefos}, title = {{Nokoyawa Ransomware | New Karma/Nemty Variant Wears Thin Disguise}}, date = {2022-04-21}, organization = {Sentinel LABS}, url = {https://www.sentinelone.com/labs/nokoyawa-ransomware-new-karma-nemty-variant-wears-thin-disguise/}, language = {English}, urldate = {2022-04-24} } Nokoyawa Ransomware | New Karma/Nemty Variant Wears Thin Disguise
Hive Karma Nemty Nokoyawa Ransomware
2022-03-09TrendmicroDon Ovid Ladores
@online{ladores:20220309:new:b6c2c2a, author = {Don Ovid Ladores}, title = {{New Nokoyawa Ransomware Possibly Related to Hive}}, date = {2022-03-09}, organization = {Trendmicro}, url = {https://www.trendmicro.com/en_us/research/22/c/nokoyawa-ransomware-possibly-related-to-hive-.html}, language = {English}, urldate = {2022-03-10} } New Nokoyawa Ransomware Possibly Related to Hive
Nokoyawa Ransomware
Yara Rules
[TLP:WHITE] win_nokoyawa_auto (20220808 | Detects win.nokoyawa.)
rule win_nokoyawa_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-08-05"
        version = "1"
        description = "Detects win.nokoyawa."
        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.nokoyawa"
        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 = { e8???????? 4883c448 c3 89542410 894c2408 }
            // n = 5, score = 100
            //   e8????????           |                     
            //   4883c448             | dec                 esp
            //   c3                   | add                 eax, edx
            //   89542410             | dec                 ecx
            //   894c2408             | mov                 edx, eax

        $sequence_1 = { 744a 488b442420 0fb700 83f85c }
            // n = 4, score = 100
            //   744a                 | dec                 eax
            //   488b442420           | mov                 ecx, dword ptr [esp + 0x30]
            //   0fb700               | dec                 eax
            //   83f85c               | mov                 edx, dword ptr [esp + 0x48]

        $sequence_2 = { c1e908 81e100ff0000 0bc1 488b4c2468 8b09 c1e918 0bc1 }
            // n = 7, score = 100
            //   c1e908               | mov                 dword ptr [ecx + 0x30], eax
            //   81e100ff0000         | dec                 eax
            //   0bc1                 | mov                 eax, dword ptr [esp + 0x30]
            //   488b4c2468           | dec                 eax
            //   8b09                 | mov                 eax, dword ptr [eax + 0x30]
            //   c1e918               | dec                 eax
            //   0bc1                 | add                 eax, 0x10000

        $sequence_3 = { 4c8b442430 0fb6ca 488b542410 418b1490 d3ea 8bca 0bc1 }
            // n = 7, score = 100
            //   4c8b442430           | mov                 eax, ecx
            //   0fb6ca               | dec                 eax
            //   488b542410           | mov                 ecx, dword ptr [esp + 0x40]
            //   418b1490             | mov                 dword ptr [ecx], eax
            //   d3ea                 | dec                 eax
            //   8bca                 | mov                 eax, dword ptr [esp + 0x40]
            //   0bc1                 | mov                 eax, dword ptr [eax]

        $sequence_4 = { bae9000000 488d4c2428 e8???????? 85c0 }
            // n = 4, score = 100
            //   bae9000000           | dec                 eax
            //   488d4c2428           | mov                 ecx, dword ptr [esp + 0x28]
            //   e8????????           |                     
            //   85c0                 | mov                 dword ptr [edx + ecx + 0x14], eax

        $sequence_5 = { 8b0c24 c1e91f 0bc1 898424dc000000 b804000000 486bc00d 8b8c24dc000000 }
            // n = 7, score = 100
            //   8b0c24               | dec                 eax
            //   c1e91f               | cwde                
            //   0bc1                 | dec                 eax
            //   898424dc000000       | mov                 ecx, dword ptr [esp + 0xad0]
            //   b804000000           | dec                 eax
            //   486bc00d             | mov                 edx, dword ptr [esp + 0xc0]
            //   8b8c24dc000000       | dec                 eax

        $sequence_6 = { 482b442430 4889442438 488b442438 4889442428 488b442470 488b4c2430 }
            // n = 6, score = 100
            //   482b442430           | add                 eax, dword ptr [esp + 0x28]
            //   4889442438           | dec                 eax
            //   488b442438           | mov                 ecx, dword ptr [esp + 0x70]
            //   4889442428           | mov                 dword ptr [ecx + 0x1c], eax
            //   488b442470           | dec                 eax
            //   488b4c2430           | mov                 eax, dword ptr [esp + 0x70]

        $sequence_7 = { 488b542450 4803d1 488bca ba04000000 486bd209 }
            // n = 5, score = 100
            //   488b542450           | imul                eax, eax, 1
            //   4803d1               | mov                 ecx, 0x3a
            //   488bca               | movzx               edx, word ptr [esp + 0x28]
            //   ba04000000           | mov                 word ptr [ecx + eax*2], dx
            //   486bd209             | mov                 eax, dword ptr [esp + 0x24]

        $sequence_8 = { 837c242000 750c 488b442440 0fb700 85c0 7506 }
            // n = 6, score = 100
            //   837c242000           | mov                 eax, ecx
            //   750c                 | mov                 dword ptr [esp + 0x10], eax
            //   488b442440           | mov                 eax, dword ptr [esp + 4]
            //   0fb700               | shl                 eax, 0x1e
            //   85c0                 | mov                 ecx, dword ptr [esp + 4]
            //   7506                 | add                 ecx, eax

        $sequence_9 = { 4c8d050b720000 488bd0 488b4c2440 e8???????? }
            // n = 4, score = 100
            //   4c8d050b720000       | dec                 eax
            //   488bd0               | mov                 ecx, dword ptr [esp + 0x60]
            //   488b4c2440           | dec                 eax
            //   e8????????           |                     

    condition:
        7 of them and filesize < 92160
}
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