SYMBOLCOMMON_NAMEaka. SYNONYMS
win.bistromath (Back to overview)

BISTROMATH

Actor(s): Lazarus Group


There is no description at this point.

References
2021-06-15KasperskySeongsu Park
@online{park:20210615:andariel:1e000a0, author = {Seongsu Park}, title = {{Andariel evolves to target South Korea with ransomware}}, date = {2021-06-15}, organization = {Kaspersky}, url = {https://securelist.com/andariel-evolves-to-target-south-korea-with-ransomware/102811/}, language = {English}, urldate = {2021-11-03} } Andariel evolves to target South Korea with ransomware
BISTROMATH PEBBLEDASH Tiger RAT Unidentified 081 (Andariel Ransomware)
2021-05-11QianxinRed Raindrop Team
@online{team:20210511:analysis:d95ef63, author = {Red Raindrop Team}, title = {{Analysis of a series of attacks by the suspected Lazarus organization using Daewoo Shipyard as relevant bait}}, date = {2021-05-11}, organization = {Qianxin}, url = {https://ti.qianxin.com/blog/articles/Analysis-of-attacks-by-Lazarus-using-Daewoo-shipyard-as-bait/}, language = {Chinese}, urldate = {2021-06-25} } Analysis of a series of attacks by the suspected Lazarus organization using Daewoo Shipyard as relevant bait
BISTROMATH
2021-04-19MalwarebytesHossein Jazi
@online{jazi:20210419:lazarus:dd2c372, author = {Hossein Jazi}, title = {{Lazarus APT conceals malicious code within BMP image to drop its RAT}}, date = {2021-04-19}, organization = {Malwarebytes}, url = {https://blog.malwarebytes.com/malwarebytes-news/2021/04/lazarus-apt-conceals-malicious-code-within-bmp-file-to-drop-its-rat/}, language = {English}, urldate = {2021-06-25} } Lazarus APT conceals malicious code within BMP image to drop its RAT
BISTROMATH
2020-02-25SentinelOneJim Walter
@online{walter:20200225:dprk:735f095, author = {Jim Walter}, title = {{DPRK Hidden Cobra Update: North Korean Malicious Cyber Activity}}, date = {2020-02-25}, organization = {SentinelOne}, url = {https://labs.sentinelone.com/dprk-hidden-cobra-update-north-korean-malicious-cyber-activity/}, language = {English}, urldate = {2020-02-27} } DPRK Hidden Cobra Update: North Korean Malicious Cyber Activity
ARTFULPIE BISTROMATH BUFFETLINE CHEESETRAY HOPLIGHT HOTCROISSANT SLICKSHOES
2020-02-14US-CERTUS-CERT
@online{uscert:20200214:malware:cdab5b7, author = {US-CERT}, title = {{Malware Analysis Report (AR20-045A): MAR-10265965-1.v1 - North Korean Trojan: BISTROMATH}}, date = {2020-02-14}, organization = {US-CERT}, url = {https://www.us-cert.gov/ncas/analysis-reports/ar20-045a}, language = {English}, urldate = {2020-02-27} } Malware Analysis Report (AR20-045A): MAR-10265965-1.v1 - North Korean Trojan: BISTROMATH
BISTROMATH
Yara Rules
[TLP:WHITE] win_bistromath_auto (20221125 | Detects win.bistromath.)
rule win_bistromath_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-11-21"
        version = "1"
        description = "Detects win.bistromath."
        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.bistromath"
        malpedia_rule_date = "20221118"
        malpedia_hash = "e0702e2e6d1d00da65c8a29a4ebacd0a4c59e1af"
        malpedia_version = "20221125"
        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 = { ff15???????? 3975f8 75e3 5e 8bc3 5b 5f }
            // n = 7, score = 400
            //   ff15????????         |                     
            //   3975f8               | cmp                 dword ptr [ebp - 8], esi
            //   75e3                 | jne                 0xffffffe5
            //   5e                   | pop                 esi
            //   8bc3                 | mov                 eax, ebx
            //   5b                   | pop                 ebx
            //   5f                   | pop                 edi

        $sequence_1 = { ff4514 40 8b55fc 8945f0 3b4510 0f8c72ffffff 8b5dec }
            // n = 7, score = 400
            //   ff4514               | inc                 dword ptr [ebp + 0x14]
            //   40                   | inc                 eax
            //   8b55fc               | mov                 edx, dword ptr [ebp - 4]
            //   8945f0               | mov                 dword ptr [ebp - 0x10], eax
            //   3b4510               | cmp                 eax, dword ptr [ebp + 0x10]
            //   0f8c72ffffff         | jl                  0xffffff78
            //   8b5dec               | mov                 ebx, dword ptr [ebp - 0x14]

        $sequence_2 = { ffb508ffffff e8???????? 8b85f8feffff 8d8df8feffff 83c404 50 ff30 }
            // n = 7, score = 400
            //   ffb508ffffff         | push                dword ptr [ebp - 0xf8]
            //   e8????????           |                     
            //   8b85f8feffff         | mov                 eax, dword ptr [ebp - 0x108]
            //   8d8df8feffff         | lea                 ecx, [ebp - 0x108]
            //   83c404               | add                 esp, 4
            //   50                   | push                eax
            //   ff30                 | push                dword ptr [eax]

        $sequence_3 = { c78570ffffff01000000 0f108d10ffffff 32d2 b810000000 32c9 0f28c1 660f73d808 }
            // n = 7, score = 400
            //   c78570ffffff01000000     | mov    dword ptr [ebp - 0x90], 1
            //   0f108d10ffffff       | movups              xmm1, xmmword ptr [ebp - 0xf0]
            //   32d2                 | xor                 dl, dl
            //   b810000000           | mov                 eax, 0x10
            //   32c9                 | xor                 cl, cl
            //   0f28c1               | movaps              xmm0, xmm1
            //   660f73d808           | psrldq              xmm0, 8

        $sequence_4 = { e8???????? 83c424 8bd7 8bcb 6a01 e8???????? 83c404 }
            // n = 7, score = 400
            //   e8????????           |                     
            //   83c424               | add                 esp, 0x24
            //   8bd7                 | mov                 edx, edi
            //   8bcb                 | mov                 ecx, ebx
            //   6a01                 | push                1
            //   e8????????           |                     
            //   83c404               | add                 esp, 4

        $sequence_5 = { 8b7d08 89548804 8b55d0 66c704882b00 c644880300 89548808 897c880c }
            // n = 7, score = 400
            //   8b7d08               | mov                 edi, dword ptr [ebp + 8]
            //   89548804             | mov                 dword ptr [eax + ecx*4 + 4], edx
            //   8b55d0               | mov                 edx, dword ptr [ebp - 0x30]
            //   66c704882b00         | mov                 word ptr [eax + ecx*4], 0x2b
            //   c644880300           | mov                 byte ptr [eax + ecx*4 + 3], 0
            //   89548808             | mov                 dword ptr [eax + ecx*4 + 8], edx
            //   897c880c             | mov                 dword ptr [eax + ecx*4 + 0xc], edi

        $sequence_6 = { f7412400100000 7478 8b410c 8b7908 8bcf 8944243c 23ce }
            // n = 7, score = 400
            //   f7412400100000       | test                dword ptr [ecx + 0x24], 0x1000
            //   7478                 | je                  0x7a
            //   8b410c               | mov                 eax, dword ptr [ecx + 0xc]
            //   8b7908               | mov                 edi, dword ptr [ecx + 8]
            //   8bcf                 | mov                 ecx, edi
            //   8944243c             | mov                 dword ptr [esp + 0x3c], eax
            //   23ce                 | and                 ecx, esi

        $sequence_7 = { e8???????? 83c404 8d95ecfeffff 8bce e8???????? 6804010000 8d85f0feffff }
            // n = 7, score = 400
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   8d95ecfeffff         | lea                 edx, [ebp - 0x114]
            //   8bce                 | mov                 ecx, esi
            //   e8????????           |                     
            //   6804010000           | push                0x104
            //   8d85f0feffff         | lea                 eax, [ebp - 0x110]

        $sequence_8 = { f6423808 7406 0fb74232 eb04 0fb74234 8b4b3c 0fb7f8 }
            // n = 7, score = 400
            //   f6423808             | test                byte ptr [edx + 0x38], 8
            //   7406                 | je                  8
            //   0fb74232             | movzx               eax, word ptr [edx + 0x32]
            //   eb04                 | jmp                 6
            //   0fb74234             | movzx               eax, word ptr [edx + 0x34]
            //   8b4b3c               | mov                 ecx, dword ptr [ebx + 0x3c]
            //   0fb7f8               | movzx               edi, ax

        $sequence_9 = { e8???????? ff75d4 ba44000000 8bcb ff75dc ff761c e8???????? }
            // n = 7, score = 400
            //   e8????????           |                     
            //   ff75d4               | push                dword ptr [ebp - 0x2c]
            //   ba44000000           | mov                 edx, 0x44
            //   8bcb                 | mov                 ecx, ebx
            //   ff75dc               | push                dword ptr [ebp - 0x24]
            //   ff761c               | push                dword ptr [esi + 0x1c]
            //   e8????????           |                     

    condition:
        7 of them and filesize < 33816576
}
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