SYMBOLCOMMON_NAMEaka. SYNONYMS
win.mindware (Back to overview)

Mindware


Ransomware, potential rebranding of win.sfile.

References
2022-06-06SentinelOneNiranjan Jayanand
@online{jayanand:20220606:from:0fa017a, author = {Niranjan Jayanand}, title = {{From the Front Lines | Another Rebrand? Mindware and SFile Ransomware Technical Breakdown}}, date = {2022-06-06}, organization = {SentinelOne}, url = {https://www.sentinelone.com/blog/from-the-front-lines-another-rebrand-mindware-and-sfile-ransomware-technical-breakdown/}, language = {English}, urldate = {2022-06-09} } From the Front Lines | Another Rebrand? Mindware and SFile Ransomware Technical Breakdown
Mindware Sfile
Yara Rules
[TLP:WHITE] win_mindware_auto (20220808 | Detects win.mindware.)
rule win_mindware_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-08-05"
        version = "1"
        description = "Detects win.mindware."
        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.mindware"
        malpedia_rule_date = "20220805"
        malpedia_hash = "6ec06c64bcfdbeda64eff021c766b4ce34542b71"
        malpedia_version = "20220808"
        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 = { 0fb689f0d84400 314d10 8b4d10 334dec 330d???????? }
            // n = 5, score = 100
            //   0fb689f0d84400       | movzx               ecx, byte ptr [ecx + 0x44d8f0]
            //   314d10               | xor                 dword ptr [ebp + 0x10], ecx
            //   8b4d10               | mov                 ecx, dword ptr [ebp + 0x10]
            //   334dec               | xor                 ecx, dword ptr [ebp - 0x14]
            //   330d????????         |                     

        $sequence_1 = { 660fefca f30f7f0a 660f6fd1 75c0 8d05a0914400 660f6f00 }
            // n = 6, score = 100
            //   660fefca             | pxor                xmm1, xmm2
            //   f30f7f0a             | movdqu              xmmword ptr [edx], xmm1
            //   660f6fd1             | movdqa              xmm2, xmm1
            //   75c0                 | jne                 0xffffffc2
            //   8d05a0914400         | lea                 eax, [0x4491a0]
            //   660f6f00             | movdqa              xmm0, xmmword ptr [eax]

        $sequence_2 = { c785d0ebffff90d34300 c785d4ebffff98d34300 c785d8ebffffb8d34300 c785dcebffffc0d34300 c785e0ebffffc8d34300 c785e4ebffffd0d34300 c785e8ebffffe0d34300 }
            // n = 7, score = 100
            //   c785d0ebffff90d34300     | mov    dword ptr [ebp - 0x1430], 0x43d390
            //   c785d4ebffff98d34300     | mov    dword ptr [ebp - 0x142c], 0x43d398
            //   c785d8ebffffb8d34300     | mov    dword ptr [ebp - 0x1428], 0x43d3b8
            //   c785dcebffffc0d34300     | mov    dword ptr [ebp - 0x1424], 0x43d3c0
            //   c785e0ebffffc8d34300     | mov    dword ptr [ebp - 0x1420], 0x43d3c8
            //   c785e4ebffffd0d34300     | mov    dword ptr [ebp - 0x141c], 0x43d3d0
            //   c785e8ebffffe0d34300     | mov    dword ptr [ebp - 0x1418], 0x43d3e0

        $sequence_3 = { c745fc???????? 8d55cc 52 8b4508 83c010 50 ff15???????? }
            // n = 7, score = 100
            //   c745fc????????       |                     
            //   8d55cc               | lea                 edx, [ebp - 0x34]
            //   52                   | push                edx
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   83c010               | add                 eax, 0x10
            //   50                   | push                eax
            //   ff15????????         |                     

        $sequence_4 = { 7427 8b4d0c 894d98 8b5598 8b45cc 3b4204 7f16 }
            // n = 7, score = 100
            //   7427                 | je                  0x29
            //   8b4d0c               | mov                 ecx, dword ptr [ebp + 0xc]
            //   894d98               | mov                 dword ptr [ebp - 0x68], ecx
            //   8b5598               | mov                 edx, dword ptr [ebp - 0x68]
            //   8b45cc               | mov                 eax, dword ptr [ebp - 0x34]
            //   3b4204               | cmp                 eax, dword ptr [edx + 4]
            //   7f16                 | jg                  0x18

        $sequence_5 = { 8b55fc c7424000000000 c7424400000000 ff15???????? }
            // n = 4, score = 100
            //   8b55fc               | mov                 edx, dword ptr [ebp - 4]
            //   c7424000000000       | mov                 dword ptr [edx + 0x40], 0
            //   c7424400000000       | mov                 dword ptr [edx + 0x44], 0
            //   ff15????????         |                     

        $sequence_6 = { 85c0 744b 837d1410 7515 8d8df8fdffff 51 8b5510 }
            // n = 7, score = 100
            //   85c0                 | test                eax, eax
            //   744b                 | je                  0x4d
            //   837d1410             | cmp                 dword ptr [ebp + 0x14], 0x10
            //   7515                 | jne                 0x17
            //   8d8df8fdffff         | lea                 ecx, [ebp - 0x208]
            //   51                   | push                ecx
            //   8b5510               | mov                 edx, dword ptr [ebp + 0x10]

        $sequence_7 = { 6a00 8b856cffffff 50 8b8d68ffffff 51 8b55bc 52 }
            // n = 7, score = 100
            //   6a00                 | push                0
            //   8b856cffffff         | mov                 eax, dword ptr [ebp - 0x94]
            //   50                   | push                eax
            //   8b8d68ffffff         | mov                 ecx, dword ptr [ebp - 0x98]
            //   51                   | push                ecx
            //   8b55bc               | mov                 edx, dword ptr [ebp - 0x44]
            //   52                   | push                edx

        $sequence_8 = { c78540f1ffffbce04300 c78544f1ffffc4e04300 c78548f1ffffcce04300 c7854cf1ffffd4e04300 c78550f1ffffe0e04300 c78554f1ffffece04300 c78558f1fffff4e04300 }
            // n = 7, score = 100
            //   c78540f1ffffbce04300     | mov    dword ptr [ebp - 0xec0], 0x43e0bc
            //   c78544f1ffffc4e04300     | mov    dword ptr [ebp - 0xebc], 0x43e0c4
            //   c78548f1ffffcce04300     | mov    dword ptr [ebp - 0xeb8], 0x43e0cc
            //   c7854cf1ffffd4e04300     | mov    dword ptr [ebp - 0xeb4], 0x43e0d4
            //   c78550f1ffffe0e04300     | mov    dword ptr [ebp - 0xeb0], 0x43e0e0
            //   c78554f1ffffece04300     | mov    dword ptr [ebp - 0xeac], 0x43e0ec
            //   c78558f1fffff4e04300     | mov    dword ptr [ebp - 0xea8], 0x43e0f4

        $sequence_9 = { c785ace9ffff60ce4300 c785b0e9ffff68ce4300 c785b4e9ffff70ce4300 c785b8e9ffff78ce4300 }
            // n = 4, score = 100
            //   c785ace9ffff60ce4300     | mov    dword ptr [ebp - 0x1654], 0x43ce60
            //   c785b0e9ffff68ce4300     | mov    dword ptr [ebp - 0x1650], 0x43ce68
            //   c785b4e9ffff70ce4300     | mov    dword ptr [ebp - 0x164c], 0x43ce70
            //   c785b8e9ffff78ce4300     | mov    dword ptr [ebp - 0x1648], 0x43ce78

    condition:
        7 of them and filesize < 661504
}
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