SYMBOLCOMMON_NAMEaka. SYNONYMS
win.data_exfiltrator (Back to overview)

DataExfiltrator

aka: FileSender

There is no description at this point.

References
2021-07-15ReversingLabsRobert Simmons
@online{simmons:20210715:data:8286b8f, author = {Robert Simmons}, title = {{Data Exfiltrator - A New Tactic for Ransomware Adversaries}}, date = {2021-07-15}, organization = {ReversingLabs}, url = {https://blog.reversinglabs.com/blog/data-exfiltrator}, language = {English}, urldate = {2021-07-20} } Data Exfiltrator - A New Tactic for Ransomware Adversaries
DataExfiltrator
Yara Rules
[TLP:WHITE] win_data_exfiltrator_auto (20230715 | Detects win.data_exfiltrator.)
rule win_data_exfiltrator_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        version = "1"
        description = "Detects win.data_exfiltrator."
        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.data_exfiltrator"
        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 = { 4889442448 48c744242800000000 48837c247000 7e0c b801000000 6689442420 eb07 }
            // n = 7, score = 100
            //   4889442448           | dec                 eax
            //   48c744242800000000     | mov    dword ptr [esp + 0x40], eax
            //   48837c247000         | dec                 eax
            //   7e0c                 | mov                 eax, dword ptr [esp + 0x40]
            //   b801000000           | cmp                 dword ptr [eax], 0x4550
            //   6689442420           | dec                 eax
            //   eb07                 | mov                 ecx, dword ptr [esp + 0x100]

        $sequence_1 = { ffc8 4898 488b4c2430 488d0441 }
            // n = 4, score = 100
            //   ffc8                 | mov                 edx, eax
            //   4898                 | dec                 eax
            //   488b4c2430           | mov                 ecx, dword ptr [esp + 0x108]
            //   488d0441             | test                eax, eax

        $sequence_2 = { 8844242c 0fb644242c 85c0 740d 0fb644242d 85c0 0f8479010000 }
            // n = 7, score = 100
            //   8844242c             | mov                 ecx, dword ptr [esp + 0x88]
            //   0fb644242c           | mov                 ecx, 0x4038
            //   85c0                 | dec                 eax
            //   740d                 | mov                 dword ptr [esp + 0x78], eax
            //   0fb644242d           | mov                 eax, dword ptr [esp + 0x58]
            //   85c0                 | add                 eax, 0x100
            //   0f8479010000         | mov                 eax, eax

        $sequence_3 = { 83b82440000000 762e 66ba0101 488b4c2460 e8???????? }
            // n = 5, score = 100
            //   83b82440000000       | cmp                 dword ptr [esp + 0x20], 0x7f17
            //   762e                 | dec                 eax
            //   66ba0101             | sub                 esp, 0x38
            //   488b4c2460           | dec                 eax
            //   e8????????           |                     

        $sequence_4 = { 4c89442418 4889542410 48894c2408 4883ec58 488b442460 0fb68008400000 85c0 }
            // n = 7, score = 100
            //   4c89442418           | dec                 eax
            //   4889542410           | lea                 eax, [0xffffd955]
            //   48894c2408           | mov                 cl, byte ptr [esp + 0x20]
            //   4883ec58             | dec                 eax
            //   488b442460           | mov                 ecx, dword ptr [esp + 0x40]
            //   0fb68008400000       | dec                 eax
            //   85c0                 | mov                 edx, dword ptr [esp + 0x20]

        $sequence_5 = { 5e c3 89542410 894c2408 4883ec18 837c242800 7507 }
            // n = 7, score = 100
            //   5e                   | dec                 eax
            //   c3                   | mov                 eax, ecx
            //   89542410             | mov                 ecx, dword ptr [esp + 0x24]
            //   894c2408             | dec                 eax
            //   4883ec18             | mov                 edx, dword ptr [esp + 0xa0]
            //   837c242800           | mov                 eax, dword ptr [eax + 0x1c]
            //   7507                 | dec                 eax

        $sequence_6 = { 488b8424c8000000 4825ffff0000 6689442420 488b442430 8b4010 }
            // n = 5, score = 100
            //   488b8424c8000000     | dec                 eax
            //   4825ffff0000         | mov                 ecx, dword ptr [ecx + 0x4018]
            //   6689442420           | dec                 eax
            //   488b442430           | mov                 edx, dword ptr [esp + 0x10]
            //   8b4010               | mov                 byte ptr [edx + ecx], al

        $sequence_7 = { c6401000 48c744243000000000 c744242880000000 c744242003000000 4533c9 4533c0 }
            // n = 6, score = 100
            //   c6401000             | dec                 eax
            //   48c744243000000000     | mov    edx, dword ptr [esp + 0x20]
            //   c744242880000000     | mov                 dword ptr [ecx + edx*4 + 8], eax
            //   c744242003000000     | xor                 edx, edx
            //   4533c9               | mov                 ecx, 0x40000
            //   4533c0               | dec                 eax

        $sequence_8 = { 0fb68008400000 85c0 7518 488b4c2460 e8???????? 66ba0001 488b4c2460 }
            // n = 7, score = 100
            //   0fb68008400000       | mov                 ecx, dword ptr [esp + 0x30]
            //   85c0                 | dec                 eax
            //   7518                 | mov                 eax, dword ptr [esp + 0x30]
            //   488b4c2460           | dec                 eax
            //   e8????????           |                     
            //   66ba0001             | add                 esp, 0xe8
            //   488b4c2460           | ret                 

        $sequence_9 = { c64424346d c64424354f c644243672 c644243778 c644243878 }
            // n = 5, score = 100
            //   c64424346d           | jae                 0x1b5
            //   c64424354f           | dec                 eax
            //   c644243672           | mov                 eax, dword ptr [esp + 0x20]
            //   c644243778           | mov                 ecx, dword ptr [eax]
            //   c644243878           | test                eax, eax

    condition:
        7 of them and filesize < 107520
}
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