rule win_strelastealer_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        version = "1"
        description = "Detects win.strelastealer."
        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.strelastealer"
        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 = { bf09000000 e8???????? 8b7c2434 83c404 50 8d0437 }
            // n = 6, score = 100
            //   bf09000000           | mov                 edi, 9
            //   e8????????           |                     
            //   8b7c2434             | mov                 edi, dword ptr [esp + 0x34]
            //   83c404               | add                 esp, 4
            //   50                   | push                eax
            //   8d0437               | lea                 eax, [edi + esi]

        $sequence_1 = { 4983e1e0 4d8bd9 49c1eb05 478b9c9a64e00100 }
            // n = 4, score = 100
            //   4983e1e0             | dec                 eax
            //   4d8bd9               | lea                 edx, [0x15f46]
            //   49c1eb05             | xor                 ecx, ecx
            //   478b9c9a64e00100     | dec                 ecx

        $sequence_2 = { 33cc e8???????? 81c484050000 c3 }
            // n = 4, score = 100
            //   33cc                 | xor                 ecx, esp
            //   e8????????           |                     
            //   81c484050000         | add                 esp, 0x584
            //   c3                   | ret                 

        $sequence_3 = { 418d511a ff15???????? 488d15e9620100 488d4c2440 ff15???????? }
            // n = 5, score = 100
            //   418d511a             | dec                 eax
            //   ff15????????         |                     
            //   488d15e9620100       | mov                 ebx, ecx
            //   488d4c2440           | dec                 eax
            //   ff15????????         |                     

        $sequence_4 = { 57 33ff 8db7c0b30010 ff36 }
            // n = 4, score = 100
            //   57                   | push                edi
            //   33ff                 | xor                 edi, edi
            //   8db7c0b30010         | lea                 esi, [edi + 0x1000b3c0]
            //   ff36                 | push                dword ptr [esi]

        $sequence_5 = { 8bd9 4c8d0d2de10000 b901000000 4c8d0519e10000 488d151ae10000 e8???????? 8bcb }
            // n = 7, score = 100
            //   8bd9                 | and                 ecx, 0xffffffe0
            //   4c8d0d2de10000       | dec                 ebp
            //   b901000000           | mov                 ebx, ecx
            //   4c8d0519e10000       | dec                 ecx
            //   488d151ae10000       | shr                 ebx, 5
            //   e8????????           |                     
            //   8bcb                 | inc                 edi

        $sequence_6 = { b804000000 8945d0 8945d4 488d05bd430100 488945e0 895128 488d0d87a30000 }
            // n = 7, score = 100
            //   b804000000           | lea                 edx, [0xe11a]
            //   8945d0               | mov                 ecx, ebx
            //   8945d4               | dec                 eax
            //   488d05bd430100       | lea                 ecx, [0x14379]
            //   488945e0             | dec                 eax
            //   895128               | lea                 ecx, [0x14385]
            //   488d0d87a30000       | mov                 al, 1

        $sequence_7 = { 6804010000 8d842480030000 53 50 e8???????? 6804010000 }
            // n = 6, score = 100
            //   6804010000           | push                0x104
            //   8d842480030000       | lea                 eax, [esp + 0x380]
            //   53                   | push                ebx
            //   50                   | push                eax
            //   e8????????           |                     
            //   6804010000           | push                0x104

        $sequence_8 = { bf0d000000 e8???????? 83c404 50 8d44245c }
            // n = 5, score = 100
            //   bf0d000000           | mov                 edi, 0xd
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   50                   | push                eax
            //   8d44245c             | lea                 eax, [esp + 0x5c]

        $sequence_9 = { e8???????? 4533c9 4c8d054d5f0100 488d15465f0100 33c9 }
            // n = 5, score = 100
            //   e8????????           |                     
            //   4533c9               | inc                 ebp
            //   4c8d054d5f0100       | xor                 ecx, ecx
            //   488d15465f0100       | dec                 esp
            //   33c9                 | lea                 eax, [0x15f4d]

        $sequence_10 = { 488bd9 488bc2 488d0d61c50000 0f57c0 48890b }
            // n = 5, score = 100
            //   488bd9               | lea                 ecx, [0xe12d]
            //   488bc2               | mov                 ecx, 1
            //   488d0d61c50000       | dec                 esp
            //   0f57c0               | lea                 eax, [0xe119]
            //   48890b               | dec                 eax

        $sequence_11 = { 305108 ffd5 85c0 751b 8d8c2488060000 51 8d94247c040000 }
            // n = 7, score = 100
            //   305108               | xor                 byte ptr [ecx + 8], dl
            //   ffd5                 | call                ebp
            //   85c0                 | test                eax, eax
            //   751b                 | jne                 0x1d
            //   8d8c2488060000       | lea                 ecx, [esp + 0x688]
            //   51                   | push                ecx
            //   8d94247c040000       | lea                 edx, [esp + 0x47c]

        $sequence_12 = { 488d0d79430100 e8???????? 488d0d85430100 e8???????? b001 }
            // n = 5, score = 100
            //   488d0d79430100       | mov                 ebx, dword ptr [edx + ebx*4 + 0x1e064]
            //   e8????????           |                     
            //   488d0d85430100       | mov                 ebx, ecx
            //   e8????????           |                     
            //   b001                 | dec                 esp

        $sequence_13 = { 33db 5e 57 ff15???????? 5f }
            // n = 5, score = 100
            //   33db                 | xor                 ebx, ebx
            //   5e                   | pop                 esi
            //   57                   | push                edi
            //   ff15????????         |                     
            //   5f                   | pop                 edi

        $sequence_14 = { 89442434 89442438 8d442434 50 6a01 53 53 }
            // n = 7, score = 100
            //   89442434             | mov                 dword ptr [esp + 0x34], eax
            //   89442438             | mov                 dword ptr [esp + 0x38], eax
            //   8d442434             | lea                 eax, [esp + 0x34]
            //   50                   | push                eax
            //   6a01                 | push                1
            //   53                   | push                ebx
            //   53                   | push                ebx

        $sequence_15 = { 8918 e8???????? 84c0 7473 e8???????? 488d0d2c080000 }
            // n = 6, score = 100
            //   8918                 | mov                 eax, edx
            //   e8????????           |                     
            //   84c0                 | dec                 eax
            //   7473                 | lea                 ecx, [0xc561]
            //   e8????????           |                     
            //   488d0d2c080000       | xorps               xmm0, xmm0

    condition:
        7 of them and filesize < 266240
}

rule win_strelastealer_w0 {
    meta:
	    description = "detect_StrelaStealer"
	    author = "@malgamy12"
	    date = "2022/11/12"
	    license = "DRL 1.1"
        hash = "6e8a3ffffd2f7a91f3f845b78dd90011feb80d30b4fe48cb174b629afa273403"
        
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.strelastealer"
        malpedia_rule_date = "20230118"
        malpedia_hash = ""
        malpedia_version = "20230118"
        malpedia_license = "DRL 1.1"
        malpedia_sharing = "TLP:WHITE"

    strings:
        $pdb = "StrelaDLLCompile.pdb" ascii

        $s1 = "4f3855aa-af7e-4fd2-b04e-55e63653d2f7" ascii
        $s2 = "StrelaDLLCompile.dll" ascii

        $chunk_1 = {33 D2 8B C7 F7 F3 8D 04 2E 83 C7 ?? 83 C6 ?? 8A 92 [4] 30 56 ?? 33 D2 F7 F3 8A 82 [4] 30 46 ?? 83 FF ??} 

        
    condition:
        uint16(0) == 0x5A4D  and ($pdb  or  (1 of ($s*) and $chunk_1 ))

}