SYMBOLCOMMON_NAMEaka. SYNONYMS
win.lowball (Back to overview)

LOWBALL

Actor(s): Temper Panda


LOWBALL, uses the legitimate Dropbox cloud-storage
service to act as the CnC server. It uses the Dropbox API with a hardcoded bearer access token and has the ability to download, upload, and execute files. The communication occurs via HTTPS over port 443.

References
2019-08-12Kindred SecurityKindred Security
@online{security:20190812:overview:0726c0a, author = {Kindred Security}, title = {{An Overview of Public Platform C2’s}}, date = {2019-08-12}, organization = {Kindred Security}, url = {https://kindredsec.wordpress.com/2019/08/12/an-overview-of-public-platform-c2s/}, language = {English}, urldate = {2021-07-20} } An Overview of Public Platform C2’s
HTML5 Encoding LOWBALL Makadocs MiniDuke RogueRobinNET RokRAT
2015-12-01FireEyeFireEye Threat Intelligence
@online{intelligence:20151201:chinabased:8836a81, author = {FireEye Threat Intelligence}, title = {{China-based Cyber Threat Group Uses Dropbox for Malware Communications and Targets Hong Kong Media Outlets}}, date = {2015-12-01}, organization = {FireEye}, url = {https://www.fireeye.com/blog/threat-research/2015/11/china-based-threat.html}, language = {English}, urldate = {2019-12-20} } China-based Cyber Threat Group Uses Dropbox for Malware Communications and Targets Hong Kong Media Outlets
BUBBLEWRAP LOWBALL TEMPER PANDA
Yara Rules
[TLP:WHITE] win_lowball_auto (20230715 | Detects win.lowball.)
rule win_lowball_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        version = "1"
        description = "Detects win.lowball."
        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.lowball"
        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 = { 33c0 8dbc2425030000 c684242403000000 f3ab 66ab 8d8c2424030000 }
            // n = 6, score = 100
            //   33c0                 | xor                 eax, eax
            //   8dbc2425030000       | lea                 edi, [esp + 0x325]
            //   c684242403000000     | mov                 byte ptr [esp + 0x324], 0
            //   f3ab                 | rep stosd           dword ptr es:[edi], eax
            //   66ab                 | stosw               word ptr es:[edi], ax
            //   8d8c2424030000       | lea                 ecx, [esp + 0x324]

        $sequence_1 = { 83c408 85f6 746c 6a02 }
            // n = 4, score = 100
            //   83c408               | add                 esp, 8
            //   85f6                 | test                esi, esi
            //   746c                 | je                  0x6e
            //   6a02                 | push                2

        $sequence_2 = { f2ae f7d1 49 8be9 8b842434020000 68???????? 50 }
            // n = 7, score = 100
            //   f2ae                 | repne scasb         al, byte ptr es:[edi]
            //   f7d1                 | not                 ecx
            //   49                   | dec                 ecx
            //   8be9                 | mov                 ebp, ecx
            //   8b842434020000       | mov                 eax, dword ptr [esp + 0x234]
            //   68????????           |                     
            //   50                   | push                eax

        $sequence_3 = { 85c0 0f8452010000 a1???????? 8a0d???????? 89842420020000 }
            // n = 5, score = 100
            //   85c0                 | test                eax, eax
            //   0f8452010000         | je                  0x158
            //   a1????????           |                     
            //   8a0d????????         |                     
            //   89842420020000       | mov                 dword ptr [esp + 0x220], eax

        $sequence_4 = { 68???????? e8???????? 8b1d???????? 83c410 85c0 752d }
            // n = 6, score = 100
            //   68????????           |                     
            //   e8????????           |                     
            //   8b1d????????         |                     
            //   83c410               | add                 esp, 0x10
            //   85c0                 | test                eax, eax
            //   752d                 | jne                 0x2f

        $sequence_5 = { 8bd8 ff15???????? 56 57 6a01 }
            // n = 5, score = 100
            //   8bd8                 | mov                 ebx, eax
            //   ff15????????         |                     
            //   56                   | push                esi
            //   57                   | push                edi
            //   6a01                 | push                1

        $sequence_6 = { 57 ff15???????? 57 89442444 e8???????? }
            // n = 5, score = 100
            //   57                   | push                edi
            //   ff15????????         |                     
            //   57                   | push                edi
            //   89442444             | mov                 dword ptr [esp + 0x44], eax
            //   e8????????           |                     

        $sequence_7 = { 8d842428020000 8bcb 50 83e103 68???????? 68???????? f3a4 }
            // n = 7, score = 100
            //   8d842428020000       | lea                 eax, [esp + 0x228]
            //   8bcb                 | mov                 ecx, ebx
            //   50                   | push                eax
            //   83e103               | and                 ecx, 3
            //   68????????           |                     
            //   68????????           |                     
            //   f3a4                 | rep movsb           byte ptr es:[edi], byte ptr [esi]

        $sequence_8 = { 85f6 7420 8b542410 56 52 8d84242c020000 }
            // n = 6, score = 100
            //   85f6                 | test                esi, esi
            //   7420                 | je                  0x22
            //   8b542410             | mov                 edx, dword ptr [esp + 0x10]
            //   56                   | push                esi
            //   52                   | push                edx
            //   8d84242c020000       | lea                 eax, [esp + 0x22c]

        $sequence_9 = { 8bfa 8d94241c010000 c1e902 f3a5 8bc8 8d442418 }
            // n = 6, score = 100
            //   8bfa                 | mov                 edi, edx
            //   8d94241c010000       | lea                 edx, [esp + 0x11c]
            //   c1e902               | shr                 ecx, 2
            //   f3a5                 | rep movsd           dword ptr es:[edi], dword ptr [esi]
            //   8bc8                 | mov                 ecx, eax
            //   8d442418             | lea                 eax, [esp + 0x18]

    condition:
        7 of them and filesize < 40960
}
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