SYMBOLCOMMON_NAMEaka. SYNONYMS
win.darkdew (Back to overview)

DARKDEW


Mandiant associates this with UNC4191, this malware spreads to removable drives.

References
2022-11-28MandiantRyan Tomcik, John Wolfram, Tommy Dacanay, Geoff Ackerman
@online{tomcik:20221128:always:f073a0d, author = {Ryan Tomcik and John Wolfram and Tommy Dacanay and Geoff Ackerman}, title = {{Always Another Secret: Lifting the Haze on China-nexus Espionage in Southeast Asia}}, date = {2022-11-28}, organization = {Mandiant}, url = {https://www.mandiant.com/resources/blog/china-nexus-espionage-southeast-asia}, language = {English}, urldate = {2022-12-02} } Always Another Secret: Lifting the Haze on China-nexus Espionage in Southeast Asia
BLUEHAZE DARKDEW MISTCLOAK
2022-11-03SophosGabor Szappanos
@online{szappanos:20221103:family:666a56f, author = {Gabor Szappanos}, title = {{Family Tree: DLL-Sideloading Cases May Be Related}}, date = {2022-11-03}, organization = {Sophos}, url = {https://news.sophos.com/en-us/2022/11/03/family-tree-dll-sideloading-cases-may-be-related/}, language = {English}, urldate = {2022-12-02} } Family Tree: DLL-Sideloading Cases May Be Related
DARKDEW MISTCLOAK
Yara Rules
[TLP:WHITE] win_darkdew_auto (20230715 | Detects win.darkdew.)
rule win_darkdew_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        version = "1"
        description = "Detects win.darkdew."
        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.darkdew"
        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 = { ff75b4 83f910 8db504ffffff 8d043b 0f43b504ffffff 898514ffffff 8d041e }
            // n = 7, score = 100
            //   ff75b4               | push                dword ptr [ebp - 0x4c]
            //   83f910               | cmp                 ecx, 0x10
            //   8db504ffffff         | lea                 esi, [ebp - 0xfc]
            //   8d043b               | lea                 eax, [ebx + edi]
            //   0f43b504ffffff       | cmovae              esi, dword ptr [ebp - 0xfc]
            //   898514ffffff         | mov                 dword ptr [ebp - 0xec], eax
            //   8d041e               | lea                 eax, [esi + ebx]

        $sequence_1 = { b991000000 03f0 f3a5 8b75fc 8dbd64fbffff 81c688040000 b991000000 }
            // n = 7, score = 100
            //   b991000000           | mov                 ecx, 0x91
            //   03f0                 | add                 esi, eax
            //   f3a5                 | rep movsd           dword ptr es:[edi], dword ptr [esi]
            //   8b75fc               | mov                 esi, dword ptr [ebp - 4]
            //   8dbd64fbffff         | lea                 edi, [ebp - 0x49c]
            //   81c688040000         | add                 esi, 0x488
            //   b991000000           | mov                 ecx, 0x91

        $sequence_2 = { 8b4d08 83f801 7419 81c244020000 8955fc 3bd1 }
            // n = 6, score = 100
            //   8b4d08               | mov                 ecx, dword ptr [ebp + 8]
            //   83f801               | cmp                 eax, 1
            //   7419                 | je                  0x1b
            //   81c244020000         | add                 edx, 0x244
            //   8955fc               | mov                 dword ptr [ebp - 4], edx
            //   3bd1                 | cmp                 edx, ecx

        $sequence_3 = { 56 57 8b7d08 e9???????? 8b1f 8d049da8f50110 8b30 }
            // n = 7, score = 100
            //   56                   | push                esi
            //   57                   | push                edi
            //   8b7d08               | mov                 edi, dword ptr [ebp + 8]
            //   e9????????           |                     
            //   8b1f                 | mov                 ebx, dword ptr [edi]
            //   8d049da8f50110       | lea                 eax, [ebx*4 + 0x1001f5a8]
            //   8b30                 | mov                 esi, dword ptr [eax]

        $sequence_4 = { 8845d4 e8???????? 8bfb c645fc17 8d4f01 8a07 }
            // n = 6, score = 100
            //   8845d4               | mov                 byte ptr [ebp - 0x2c], al
            //   e8????????           |                     
            //   8bfb                 | mov                 edi, ebx
            //   c645fc17             | mov                 byte ptr [ebp - 4], 0x17
            //   8d4f01               | lea                 ecx, [edi + 1]
            //   8a07                 | mov                 al, byte ptr [edi]

        $sequence_5 = { 8bf0 3b542420 72e2 83fb08 }
            // n = 4, score = 100
            //   8bf0                 | mov                 esi, eax
            //   3b542420             | cmp                 edx, dword ptr [esp + 0x20]
            //   72e2                 | jb                  0xffffffe4
            //   83fb08               | cmp                 ebx, 8

        $sequence_6 = { 6bd738 8b0c8da0f30110 c644112800 85f6 }
            // n = 4, score = 100
            //   6bd738               | imul                edx, edi, 0x38
            //   8b0c8da0f30110       | mov                 ecx, dword ptr [ecx*4 + 0x1001f3a0]
            //   c644112800           | mov                 byte ptr [ecx + edx + 0x28], 0
            //   85f6                 | test                esi, esi

        $sequence_7 = { 0fbe8070e10110 40 8945cc 2b45dc 8945d4 3bc2 0f8f10020000 }
            // n = 7, score = 100
            //   0fbe8070e10110       | movsx               eax, byte ptr [eax + 0x1001e170]
            //   40                   | inc                 eax
            //   8945cc               | mov                 dword ptr [ebp - 0x34], eax
            //   2b45dc               | sub                 eax, dword ptr [ebp - 0x24]
            //   8945d4               | mov                 dword ptr [ebp - 0x2c], eax
            //   3bc2                 | cmp                 eax, edx
            //   0f8f10020000         | jg                  0x216

        $sequence_8 = { 8bc6 8bcf 2b4c2428 83c408 }
            // n = 4, score = 100
            //   8bc6                 | mov                 eax, esi
            //   8bcf                 | mov                 ecx, edi
            //   2b4c2428             | sub                 ecx, dword ptr [esp + 0x28]
            //   83c408               | add                 esp, 8

        $sequence_9 = { b991000000 894508 8dbda8fdffff 8bf0 8d8574fcffff 50 8d85b8feffff }
            // n = 7, score = 100
            //   b991000000           | mov                 ecx, 0x91
            //   894508               | mov                 dword ptr [ebp + 8], eax
            //   8dbda8fdffff         | lea                 edi, [ebp - 0x258]
            //   8bf0                 | mov                 esi, eax
            //   8d8574fcffff         | lea                 eax, [ebp - 0x38c]
            //   50                   | push                eax
            //   8d85b8feffff         | lea                 eax, [ebp - 0x148]

    condition:
        7 of them and filesize < 279552
}
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