SYMBOLCOMMON_NAMEaka. SYNONYMS
win.puzzlemaker (Back to overview)

puzzlemaker

Actor(s): [Unnamed group]


The dropper module is used to install two executables that pretend to be legitimate files belonging to Microsoft Windows OS. One of these files (%SYSTEM%\WmiPrvMon.exe) is registered as a service and is used as a launcher for the second executable. This second executable (%SYSTEM%\wmimon.dll) has the functionality of a remote shell and can be considered the main payload of the attack.

References
2021-06-08KasperskyBoris Larin, Costin Raiu, Alexey Kulaev
@online{larin:20210608:puzzlemaker:43c7dfa, author = {Boris Larin and Costin Raiu and Alexey Kulaev}, title = {{PuzzleMaker attacks with Chrome zero-day exploit chain}}, date = {2021-06-08}, organization = {Kaspersky}, url = {https://securelist.com/puzzlemaker-chrome-zero-day-exploit-chain/102771/}, language = {English}, urldate = {2021-06-16} } PuzzleMaker attacks with Chrome zero-day exploit chain
Chainshot puzzlemaker
Yara Rules
[TLP:WHITE] win_puzzlemaker_auto (20230715 | Detects win.puzzlemaker.)
rule win_puzzlemaker_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        version = "1"
        description = "Detects win.puzzlemaker."
        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.puzzlemaker"
        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 = { 420fb60c12 66413109 7410 41ffc0 4983c102 4181f804010000 72e1 }
            // n = 7, score = 100
            //   420fb60c12           | je                  0x734
            //   66413109             | cmp                 byte ptr [edi], 0x1a
            //   7410                 | je                  0x753
            //   41ffc0               | dec                 eax
            //   4983c102             | lea                 eax, [0x131e0]
            //   4181f804010000       | dec                 eax
            //   72e1                 | mov                 dword ptr [ecx], eax

        $sequence_1 = { 33d2 33c9 ff15???????? 488d0dfcbc0100 eb0c 83f901 750d }
            // n = 7, score = 100
            //   33d2                 | dec                 eax
            //   33c9                 | mov                 edx, dword ptr [ebx + 8]
            //   ff15????????         |                     
            //   488d0dfcbc0100       | inc                 ecx
            //   eb0c                 | inc                 eax
            //   83f901               | movzx               ecx, byte ptr [edx]
            //   750d                 | and                 ecx, 0xf

        $sequence_2 = { b001 ebe7 4c8b02 4c8d1d9a9fffff 4c8bd1 4c8bca }
            // n = 6, score = 100
            //   b001                 | mov                 eax, ebx
            //   ebe7                 | dec                 eax
            //   4c8b02               | lea                 edx, [0xa47d]
            //   4c8d1d9a9fffff       | dec                 ecx
            //   4c8bd1               | mov                 ecx, esi
            //   4c8bca               | test                eax, eax

        $sequence_3 = { 488d0d80000100 4183e23f 4d03f0 4d8bf8 498bf8 488b04c1 }
            // n = 6, score = 100
            //   488d0d80000100       | movzx               eax, word ptr [ecx]
            //   4183e23f             | dec                 eax
            //   4d03f0               | lea                 ecx, [ecx + 2]
            //   4d8bf8               | dec                 esp
            //   498bf8               | lea                 ecx, [0xa8f4]
            //   488b04c1             | subsd               xmm1, xmm2

        $sequence_4 = { e8???????? 488d05e43a0100 488903 488bc3 }
            // n = 4, score = 100
            //   e8????????           |                     
            //   488d05e43a0100       | movzx               ecx, byte ptr [edx]
            //   488903               | and                 ecx, 0xf
            //   488bc3               | dec                 edx

        $sequence_5 = { 488bd8 488945a7 4885c0 7432 }
            // n = 4, score = 100
            //   488bd8               | mov                 eax, 0x5a4d
            //   488945a7             | cmp                 word ptr [0xffffd471], ax
            //   4885c0               | dec                 eax
            //   7432                 | sub                 esp, 0x20

        $sequence_6 = { 410fb60a 83e10f 4a0fbe8419b8640100 428a8c19c8640100 }
            // n = 4, score = 100
            //   410fb60a             | lea                 ecx, [0x1bcfc]
            //   83e10f               | xor                 edx, edx
            //   4a0fbe8419b8640100     | inc    esp
            //   428a8c19c8640100     | mov                 dword ptr [esp + 0x70], ebp

        $sequence_7 = { 4c8d5101 881a 418bf1 4c8d35bdcbffff }
            // n = 4, score = 100
            //   4c8d5101             | mov                 eax, 1
            //   881a                 | dec                 eax
            //   418bf1               | lea                 eax, [0xfffed96f]
            //   4c8d35bdcbffff       | dec                 edx

        $sequence_8 = { 498b5708 0fb60a 83e10f 4a0fbe8401b8640100 }
            // n = 4, score = 100
            //   498b5708             | mov                 ecx, 0x18
            //   0fb60a               | inc                 ebp
            //   83e10f               | xor                 ebp, ebp
            //   4a0fbe8401b8640100     | dec    eax

        $sequence_9 = { 4c8d1d9a9fffff 4c8bd1 4c8bca 410fb608 83e10f }
            // n = 5, score = 100
            //   4c8d1d9a9fffff       | dec                 eax
            //   4c8bd1               | sub                 edx, eax
            //   4c8bca               | mov                 eax, dword ptr [edx - 4]
            //   410fb608             | dec                 ecx
            //   83e10f               | mov                 dword ptr [ecx + 8], edx

    condition:
        7 of them and filesize < 331776
}
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