SYMBOLCOMMON_NAMEaka. SYNONYMS
win.enigma_loader (Back to overview)

Enigma Loader


According to Trend Micro, this is a downloader, dedicated to stage execution of a second stage malware called Enigma Stealer.

References
2023-02-09Trend MicroAliakbar Zahravi, Peter Girnus
@online{zahravi:20230209:enigma:71c3a6f, author = {Aliakbar Zahravi and Peter Girnus}, title = {{Enigma Stealer Targets Cryptocurrency Industry with Fake Jobs}}, date = {2023-02-09}, organization = {Trend Micro}, url = {https://www.trendmicro.com/en_us/research/23/b/enigma-stealer-targets-cryptocurrency-industry-with-fake-jobs.html}, language = {English}, urldate = {2023-02-13} } Enigma Stealer Targets Cryptocurrency Industry with Fake Jobs
Enigma Loader
Yara Rules
[TLP:WHITE] win_enigma_loader_auto (20230715 | Detects win.enigma_loader.)
rule win_enigma_loader_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        version = "1"
        description = "Detects win.enigma_loader."
        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.enigma_loader"
        malpedia_rule_date = "20230705"
        malpedia_hash = "42d0574f4405bd7d2b154d321d345acb18834a41"
        malpedia_version = "20230715"
        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 = { 0f86a9000000 ebbb 4885c0 740d 488bc8 e8???????? 488bd8 }
            // n = 7, score = 100
            //   0f86a9000000         | test                edx, edx
            //   ebbb                 | je                  0x64e
            //   4885c0               | sub                 edx, 1
            //   740d                 | dec                 eax
            //   488bc8               | mov                 esi, dword ptr [0x60]
            //   e8????????           |                     
            //   488bd8               | dec                 eax

        $sequence_1 = { 48897010 408830 eb15 b918000000 e8???????? 48897010 48897008 }
            // n = 7, score = 100
            //   48897010             | cmp                 esi, 4
            //   408830               | jb                  0x751
            //   eb15                 | cmp                 al, byte ptr [ebp + esi + 0x10]
            //   b918000000           | jne                 0x77d
            //   e8????????           |                     
            //   48897010             | dec                 eax
            //   48897008             | add                 esi, edi

        $sequence_2 = { 0fb7c0 6bc834 664103c8 41ffc0 66413109 4d8d4902 4183f80b }
            // n = 7, score = 100
            //   0fb7c0               | mov                 eax, dword ptr [ebx]
            //   6bc834               | inc                 esp
            //   664103c8             | mov                 byte ptr [eax + ecx], cl
            //   41ffc0               | inc                 eax
            //   66413109             | mov                 byte ptr [eax + ecx + 1], ch
            //   4d8d4902             | jmp                 0x45f
            //   4183f80b             | dec                 eax

        $sequence_3 = { 7644 8b4d00 8bd3 4803cf 488bc1 3819 7409 }
            // n = 7, score = 100
            //   7644                 | mov                 byte ptr [esp + 0x30], dh
            //   8b4d00               | dec                 eax
            //   8bd3                 | mov                 dword ptr [esp + 0x38], esi
            //   4803cf               | dec                 esp
            //   488bc1               | add                 dword ptr [ecx + 8], ebp
            //   3819                 | jmp                 0xba9
            //   7409                 | dec                 esp

        $sequence_4 = { 90 41c6466801 4138b6b0000000 0f8559060000 bb00100000 488b5590 493bd5 }
            // n = 7, score = 100
            //   90                   | mov                 dword ptr [ecx], eax
            //   41c6466801           | mov                 eax, dword ptr [edx + 8]
            //   4138b6b0000000       | mov                 dword ptr [ecx + 8], eax
            //   0f8559060000         | dec                 eax
            //   bb00100000           | mov                 ecx, dword ptr [edx + 0x10]
            //   488b5590             | dec                 eax
            //   493bd5               | mov                 dword ptr [ebx + 0x10], ecx

        $sequence_5 = { 488bcb e8???????? 41894640 83f80c 0f858f020000 4088bd58020000 }
            // n = 6, score = 100
            //   488bcb               | mov                 eax, dword ptr [esp + 0xb8]
            //   e8????????           |                     
            //   41894640             | inc                 ecx
            //   83f80c               | mov                 edi, esi
            //   0f858f020000         | inc                 ebp
            //   4088bd58020000       | mov                 dword ptr [eax], esi

        $sequence_6 = { 448a4f14 0f839e000000 488d4101 48894310 4c397318 488bc3 7203 }
            // n = 7, score = 100
            //   448a4f14             | test                eax, eax
            //   0f839e000000         | je                  0x8ff
            //   488d4101             | dec                 eax
            //   48894310             | mov                 ebx, dword ptr [esp + 0x58]
            //   4c397318             | mov                 esi, 0x1ce43de8
            //   488bc3               | mov                 edx, esi
            //   7203                 | inc                 ecx

        $sequence_7 = { 4885db 740e 483bdf 0f84ac000000 e9???????? 4d8bb4f670b70200 33d2 }
            // n = 7, score = 100
            //   4885db               | and                 edx, 0xfffffffc
            //   740e                 | mov                 edi, 0x1000
            //   483bdf               | dec                 eax
            //   0f84ac000000         | mov                 edx, dword ptr [esp + 0x70]
            //   e9????????           |                     
            //   4d8bb4f670b70200     | dec                 eax
            //   33d2                 | cmp                 edx, 0x10

        $sequence_8 = { e8???????? 48894620 488bcb e8???????? 41894640 83f80c }
            // n = 6, score = 100
            //   e8????????           |                     
            //   48894620             | mov                 eax, ebx
            //   488bcb               | dec                 esp
            //   e8????????           |                     
            //   41894640             | cmp                 edi, edx
            //   83f80c               | je                  0xcc

        $sequence_9 = { 4c894018 4c894820 53 56 57 b840200000 e8???????? }
            // n = 7, score = 100
            //   4c894018             | dec                 eax
            //   4c894820             | lea                 edx, [ebp + 0x60]
            //   53                   | dec                 ecx
            //   56                   | mov                 ecx, esi
            //   57                   | nop                 
            //   b840200000           | inc                 ecx
            //   e8????????           |                     

    condition:
        7 of them and filesize < 798720
}
Download all Yara Rules