win.nymaim (Back to overview)

Nymaim

aka: nymain
URLhaus      

There is no description at this point.

References
https://www.cert.pl/en/news/single/nymaim-revisited/
https://www.justice.gov/opa/pr/goznym-cyber-criminal-network-operating-out-europe-targeting-american-entities-dismantled
https://www.shadowserver.org/news/goznym-indictments-action-following-on-from-successful-avalanche-operations/
https://www.proofpoint.com/us/threat-insight/post/nymaim-config-decoded
https://securityintelligence.com/posts/goznym-closure-comes-in-the-shape-of-a-europol-and-doj-arrest-operation/
https://bitbucket.org/daniel_plohmann/idapatchwork
https://arielkoren.com/blog/2016/11/02/nymaim-deep-technical-dive-adventures-in-evasive-malware/
https://public.gdatasoftware.com/Web/Landingpages/DE/GI-Spring2014/slides/004_plohmann.pdf
https://github.com/coldshell/Malware-Scripts/tree/master/Nymaim
https://securityintelligence.com/meet-goznym-the-banking-malware-offspring-of-gozi-isfb-and-nymaim/
Yara Rules
[TLP:WHITE] win_nymaim_auto (20190620 | autogenerated rule brought to you by yara-signator)
rule win_nymaim_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2019-07-05"
        version = "1"
        description = "autogenerated rule brought to you by yara-signator"
        tool = "yara-signator 0.2a"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.nymaim"
        malpedia_version = "20190620"
        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 / approach 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 = { 89d8 01c8 31d2 f7f7 }
            // n = 4, score = 1800
            //   89d8                 | mov                 eax, ebx
            //   01c8                 | add                 eax, ecx
            //   31d2                 | xor                 edx, edx
            //   f7f7                 | div                 edi

        $sequence_1 = { 89d8 01c8 31d2 f7f7 }
            // n = 4, score = 1800
            //   89d8                 | mov                 eax, ebx
            //   01c8                 | add                 eax, ecx
            //   31d2                 | xor                 edx, edx
            //   f7f7                 | div                 edi

        $sequence_2 = { 01c8 31d2 f7f7 92 31d2 bf64000000 }
            // n = 6, score = 1700
            //   01c8                 | add                 eax, ecx
            //   31d2                 | xor                 edx, edx
            //   f7f7                 | div                 edi
            //   92                   | xchg                eax, edx
            //   31d2                 | xor                 edx, edx
            //   bf64000000           | mov                 edi, 0x64

        $sequence_3 = { 89d8 01c8 31d2 f7f7 92 31d2 bf64000000 }
            // n = 7, score = 1700
            //   89d8                 | mov                 eax, ebx
            //   01c8                 | add                 eax, ecx
            //   31d2                 | xor                 edx, edx
            //   f7f7                 | div                 edi
            //   92                   | xchg                eax, edx
            //   31d2                 | xor                 edx, edx
            //   bf64000000           | mov                 edi, 0x64

        $sequence_4 = { 92 31d2 bf64000000 f7f7 }
            // n = 4, score = 1700
            //   92                   | xchg                eax, edx
            //   31d2                 | xor                 edx, edx
            //   bf64000000           | mov                 edi, 0x64
            //   f7f7                 | div                 edi

        $sequence_5 = { e8???????? 83f800 0f8????????? 89c7 }
            // n = 4, score = 1700
            //   e8????????           |                     
            //   83f800               | cmp                 eax, 0
            //   0f8?????????         |                     
            //   89c7                 | mov                 edi, eax

        $sequence_6 = { 01c8 31d2 f7f7 92 31d2 }
            // n = 5, score = 1700
            //   01c8                 | add                 eax, ecx
            //   31d2                 | xor                 edx, edx
            //   f7f7                 | div                 edi
            //   92                   | xchg                eax, edx
            //   31d2                 | xor                 edx, edx

        $sequence_7 = { 31d2 f7f7 92 31d2 }
            // n = 4, score = 1700
            //   31d2                 | xor                 edx, edx
            //   f7f7                 | div                 edi
            //   92                   | xchg                eax, edx
            //   31d2                 | xor                 edx, edx

        $sequence_8 = { 6bc064 09c0 0f8????????? 89c7 }
            // n = 4, score = 1700
            //   6bc064               | imul                eax, eax, 0x64
            //   09c0                 | or                  eax, eax
            //   0f8?????????         |                     
            //   89c7                 | mov                 edi, eax

        $sequence_9 = { 31d2 f7f7 92 31d2 bf64000000 }
            // n = 5, score = 1700
            //   31d2                 | xor                 edx, edx
            //   f7f7                 | div                 edi
            //   92                   | xchg                eax, edx
            //   31d2                 | xor                 edx, edx
            //   bf64000000           | mov                 edi, 0x64

        $sequence_10 = { 89d8 01c8 31d2 f7f7 92 }
            // n = 5, score = 1700
            //   89d8                 | mov                 eax, ebx
            //   01c8                 | add                 eax, ecx
            //   31d2                 | xor                 edx, edx
            //   f7f7                 | div                 edi
            //   92                   | xchg                eax, edx

        $sequence_11 = { 8b5f04 8b0f 09c3 0f8????????? }
            // n = 4, score = 1600
            //   8b5f04               | mov                 ebx, dword ptr [edi + 4]
            //   8b0f                 | mov                 ecx, dword ptr [edi]
            //   09c3                 | or                  ebx, eax
            //   0f8?????????         |                     

        $sequence_12 = { 38f0 83d100 38d0 83d900 }
            // n = 4, score = 1600
            //   38f0                 | cmp                 al, dh
            //   83d100               | adc                 ecx, 0
            //   38d0                 | cmp                 al, dl
            //   83d900               | sbb                 ecx, 0

        $sequence_13 = { 31db 83f801 0f8????????? 8a06 }
            // n = 4, score = 1600
            //   31db                 | xor                 ebx, ebx
            //   83f801               | cmp                 eax, 1
            //   0f8?????????         |                     
            //   8a06                 | mov                 al, byte ptr [esi]

        $sequence_14 = { 83e103 c1e103 89d8 d3c8 }
            // n = 4, score = 1600
            //   83e103               | and                 ecx, 3
            //   c1e103               | shl                 ecx, 3
            //   89d8                 | mov                 eax, ebx
            //   d3c8                 | ror                 eax, cl

        $sequence_15 = { 5d c3 55 89e5 6a00 682030d201 }
            // n = 6, score = 100
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   55                   | push                ebp
            //   89e5                 | mov                 ebp, esp
            //   6a00                 | push                0
            //   682030d201           | push                0x1d23020

        $sequence_16 = { 5b 5d c3 8b45f0 8b0c850440d201 8b55f8 39d1 }
            // n = 7, score = 100
            //   5b                   | pop                 ebx
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   8b45f0               | mov                 eax, dword ptr [ebp - 0x10]
            //   8b0c850440d201       | mov                 ecx, dword ptr [eax*4 + 0x1d24004]
            //   8b55f8               | mov                 edx, dword ptr [ebp - 8]
            //   39d1                 | cmp                 ecx, edx

        $sequence_17 = { c7424400100000 c7424800e00700 8b7de4 c787cc00000000000000 c787c800000000000000 8945dc }
            // n = 6, score = 100
            //   c7424400100000       | mov                 dword ptr [edx + 0x44], 0x1000
            //   c7424800e00700       | mov                 dword ptr [edx + 0x48], 0x7e000
            //   8b7de4               | mov                 edi, dword ptr [ebp - 0x1c]
            //   c787cc00000000000000     | mov    dword ptr [edi + 0xcc], 0
            //   c787c800000000000000     | mov    dword ptr [edi + 0xc8], 0
            //   8945dc               | mov                 dword ptr [ebp - 0x24], eax

        $sequence_18 = { 8b55f4 8b75ec 89723c c7424003000000 }
            // n = 4, score = 100
            //   8b55f4               | mov                 edx, dword ptr [ebp - 0xc]
            //   8b75ec               | mov                 esi, dword ptr [ebp - 0x14]
            //   89723c               | mov                 dword ptr [edx + 0x3c], esi
            //   c7424003000000       | mov                 dword ptr [edx + 0x40], 3

        $sequence_19 = { 8b75ec 89723c c7424003000000 c7424400100000 c7424800e00700 8b7de4 c787cc00000000000000 }
            // n = 7, score = 100
            //   8b75ec               | mov                 esi, dword ptr [ebp - 0x14]
            //   89723c               | mov                 dword ptr [edx + 0x3c], esi
            //   c7424003000000       | mov                 dword ptr [edx + 0x40], 3
            //   c7424400100000       | mov                 dword ptr [edx + 0x44], 0x1000
            //   c7424800e00700       | mov                 dword ptr [edx + 0x48], 0x7e000
            //   8b7de4               | mov                 edi, dword ptr [ebp - 0x1c]
            //   c787cc00000000000000     | mov    dword ptr [edi + 0xcc], 0

        $sequence_20 = { 89e5 6a00 682030d201 e8???????? 83c408 }
            // n = 5, score = 100
            //   89e5                 | mov                 ebp, esp
            //   6a00                 | push                0
            //   682030d201           | push                0x1d23020
            //   e8????????           |                     
            //   83c408               | add                 esp, 8

        $sequence_21 = { 8b55f4 8b75ec 89723c c7424003000000 c7424400100000 c7424800e00700 8b7de4 }
            // n = 7, score = 100
            //   8b55f4               | mov                 edx, dword ptr [ebp - 0xc]
            //   8b75ec               | mov                 esi, dword ptr [ebp - 0x14]
            //   89723c               | mov                 dword ptr [edx + 0x3c], esi
            //   c7424003000000       | mov                 dword ptr [edx + 0x40], 3
            //   c7424400100000       | mov                 dword ptr [edx + 0x44], 0x1000
            //   c7424800e00700       | mov                 dword ptr [edx + 0x48], 0x7e000
            //   8b7de4               | mov                 edi, dword ptr [ebp - 0x1c]

        $sequence_22 = { 83c414 5b 5d c3 8b45f0 8b0c850440d201 }
            // n = 6, score = 100
            //   83c414               | add                 esp, 0x14
            //   5b                   | pop                 ebx
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   8b45f0               | mov                 eax, dword ptr [ebp - 0x10]
            //   8b0c850440d201       | mov                 ecx, dword ptr [eax*4 + 0x1d24004]

    condition:
        7 of them
}
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