SYMBOLCOMMON_NAMEaka. SYNONYMS
win.nachocheese (Back to overview)

NACHOCHEESE

aka: Cyruslish, TWOPENCE, VIVACIOUSGIFT

Actor(s): Lazarus Group


According to FireEye, NACHOCHEESE is a command-line tunneler that accepts delimited C&C IPs or domains via command-line and gives actors shell access to a victim's system.

References
2020-08-26CISACISA
@online{cisa:20200826:mar103017062v1:e64b3ac, author = {CISA}, title = {{MAR-10301706-2.v1 - North Korean Remote Access Tool: VIVACIOUSGIFT}}, date = {2020-08-26}, organization = {CISA}, url = {https://us-cert.cisa.gov/ncas/analysis-reports/ar20-239b}, language = {English}, urldate = {2020-09-01} } MAR-10301706-2.v1 - North Korean Remote Access Tool: VIVACIOUSGIFT
NACHOCHEESE
2020-02-19LexfoLexfo
@techreport{lexfo:20200219:lazarus:f293c37, author = {Lexfo}, title = {{The Lazarus Constellation A study on North Korean malware}}, date = {2020-02-19}, institution = {Lexfo}, url = {https://blog.lexfo.fr/ressources/Lexfo-WhitePaper-The_Lazarus_Constellation.pdf}, language = {English}, urldate = {2020-03-11} } The Lazarus Constellation A study on North Korean malware
FastCash AppleJeus BADCALL Bankshot Brambul Dtrack Duuzer DYEPACK ELECTRICFISH HARDRAIN Hermes HOPLIGHT Joanap KEYMARBLE Kimsuky MimiKatz MyDoom NACHOCHEESE NavRAT PowerRatankba RokRAT Sierra(Alfa,Bravo, ...) Volgmer WannaCryptor
2018FireEyeFireEye
@techreport{fireeye:2018:apt38:c81b87d, author = {FireEye}, title = {{APT38}}, date = {2018}, institution = {FireEye}, url = {https://www.fireeye.com/content/dam/fireeye-www/current-threats/pdfs/pf/apt/rpt-apt38-2018.pdf}, language = {English}, urldate = {2020-01-07} } APT38
CHEESETRAY CLEANTOAD NACHOCHEESE
2017-02-20BAE SystemsSergei Shevchenko
@online{shevchenko:20170220:lazarus:c608fd5, author = {Sergei Shevchenko}, title = {{Lazarus’ False Flag Malware}}, date = {2017-02-20}, organization = {BAE Systems}, url = {https://baesystemsai.blogspot.com/2017/02/lazarus-false-flag-malware.html}, language = {English}, urldate = {2019-12-20} } Lazarus’ False Flag Malware
NACHOCHEESE
2017-02-16ESET ResearchPeter Kálnai
@online{klnai:20170216:demystifying:7ae8785, author = {Peter Kálnai}, title = {{Demystifying targeted malware used against Polish banks}}, date = {2017-02-16}, organization = {ESET Research}, url = {https://www.welivesecurity.com/2017/02/16/demystifying-targeted-malware-used-polish-banks/}, language = {English}, urldate = {2019-11-14} } Demystifying targeted malware used against Polish banks
HOTWAX NACHOCHEESE
Yara Rules
[TLP:WHITE] win_nachocheese_auto (20220411 | Detects win.nachocheese.)
rule win_nachocheese_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-04-08"
        version = "1"
        description = "Detects win.nachocheese."
        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.nachocheese"
        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 = { 8955fc 53 b9???????? 2bc8 ba???????? bb???????? }
            // n = 6, score = 300
            //   8955fc               | mov                 dword ptr [ebp - 4], edx
            //   53                   | push                ebx
            //   b9????????           |                     
            //   2bc8                 | sub                 ecx, eax
            //   ba????????           |                     
            //   bb????????           |                     

        $sequence_1 = { 8945fc eb58 8b0d???????? 8d4604 }
            // n = 4, score = 300
            //   8945fc               | mov                 dword ptr [ebp - 4], eax
            //   eb58                 | jmp                 0x5a
            //   8b0d????????         |                     
            //   8d4604               | lea                 eax, dword ptr [esi + 4]

        $sequence_2 = { ff15???????? 8b45f4 6a00 50 }
            // n = 4, score = 300
            //   ff15????????         |                     
            //   8b45f4               | mov                 eax, dword ptr [ebp - 0xc]
            //   6a00                 | push                0
            //   50                   | push                eax

        $sequence_3 = { 3d9c000000 7c07 3d9f000000 7e0d }
            // n = 4, score = 300
            //   3d9c000000           | cmp                 eax, 0x9c
            //   7c07                 | jl                  9
            //   3d9f000000           | cmp                 eax, 0x9f
            //   7e0d                 | jle                 0xf

        $sequence_4 = { 43 84c0 75b6 88041f 8b4dfc }
            // n = 5, score = 300
            //   43                   | inc                 ebx
            //   84c0                 | test                al, al
            //   75b6                 | jne                 0xffffffb8
            //   88041f               | mov                 byte ptr [edi + ebx], al
            //   8b4dfc               | mov                 ecx, dword ptr [ebp - 4]

        $sequence_5 = { 83c408 fec3 85f6 0f8539ffffff b8???????? 8d5001 8a08 }
            // n = 7, score = 300
            //   83c408               | add                 esp, 8
            //   fec3                 | inc                 bl
            //   85f6                 | test                esi, esi
            //   0f8539ffffff         | jne                 0xffffff3f
            //   b8????????           |                     
            //   8d5001               | lea                 edx, dword ptr [eax + 1]
            //   8a08                 | mov                 cl, byte ptr [eax]

        $sequence_6 = { 3d2bc00000 7d1b 3d9c000000 7c07 }
            // n = 4, score = 300
            //   3d2bc00000           | cmp                 eax, 0xc02b
            //   7d1b                 | jge                 0x1d
            //   3d9c000000           | cmp                 eax, 0x9c
            //   7c07                 | jl                  9

        $sequence_7 = { 7305 83c302 eb29 81fb00010000 }
            // n = 4, score = 300
            //   7305                 | jae                 7
            //   83c302               | add                 ebx, 2
            //   eb29                 | jmp                 0x2b
            //   81fb00010000         | cmp                 ebx, 0x100

        $sequence_8 = { 51 8dbde4f9ffff 8d85e4fdffff e8???????? }
            // n = 4, score = 300
            //   51                   | push                ecx
            //   8dbde4f9ffff         | lea                 edi, dword ptr [ebp - 0x61c]
            //   8d85e4fdffff         | lea                 eax, dword ptr [ebp - 0x21c]
            //   e8????????           |                     

        $sequence_9 = { 33c0 c3 05d13fffff 83f801 }
            // n = 4, score = 300
            //   33c0                 | xor                 eax, eax
            //   c3                   | ret                 
            //   05d13fffff           | add                 eax, 0xffff3fd1
            //   83f801               | cmp                 eax, 1

        $sequence_10 = { 33c8 894710 8b4708 33c1 }
            // n = 4, score = 300
            //   33c8                 | xor                 ecx, eax
            //   894710               | mov                 dword ptr [edi + 0x10], eax
            //   8b4708               | mov                 eax, dword ptr [edi + 8]
            //   33c1                 | xor                 eax, ecx

        $sequence_11 = { 3d2cc00000 7f18 3d2bc00000 7d1b }
            // n = 4, score = 300
            //   3d2cc00000           | cmp                 eax, 0xc02c
            //   7f18                 | jg                  0x1a
            //   3d2bc00000           | cmp                 eax, 0xc02b
            //   7d1b                 | jge                 0x1d

        $sequence_12 = { 8d95f8feffff e8???????? 8b4dfc 33cd e8???????? }
            // n = 5, score = 300
            //   8d95f8feffff         | lea                 edx, dword ptr [ebp - 0x108]
            //   e8????????           |                     
            //   8b4dfc               | mov                 ecx, dword ptr [ebp - 4]
            //   33cd                 | xor                 ecx, ebp
            //   e8????????           |                     

        $sequence_13 = { 2bfa 8d47fd 3901 8901 }
            // n = 4, score = 300
            //   2bfa                 | sub                 edi, edx
            //   8d47fd               | lea                 eax, dword ptr [edi - 3]
            //   3901                 | cmp                 dword ptr [ecx], eax
            //   8901                 | mov                 dword ptr [ecx], eax

        $sequence_14 = { 3d9f000000 7e0d 33c0 c3 }
            // n = 4, score = 300
            //   3d9f000000           | cmp                 eax, 0x9f
            //   7e0d                 | jle                 0xf
            //   33c0                 | xor                 eax, eax
            //   c3                   | ret                 

        $sequence_15 = { 8895f0fcffff 8d95f1fcffff 6a00 52 e8???????? 6a3a }
            // n = 6, score = 300
            //   8895f0fcffff         | mov                 byte ptr [ebp - 0x310], dl
            //   8d95f1fcffff         | lea                 edx, dword ptr [ebp - 0x30f]
            //   6a00                 | push                0
            //   52                   | push                edx
            //   e8????????           |                     
            //   6a3a                 | push                0x3a

    condition:
        7 of them and filesize < 1064960
}
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