rule win_computrace_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.computrace."
        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.computrace"
        malpedia_rule_date = "20260916"
        malpedia_hash = "53a643781c18e08f4a50949af60172d837a0b6f6"
        malpedia_version = "20260917"
        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 = { 56 56 a1???????? ff7034 ff75cc e8???????? }
            // n = 6, score = 200
            //   56                   | push                esi
            //   56                   | push                esi
            //   a1????????           |                     
            //   ff7034               | push                dword ptr [eax + 0x34]
            //   ff75cc               | push                dword ptr [ebp - 0x34]
            //   e8????????           |                     

        $sequence_1 = { 53 53 53 53 68???????? ff560c 3bc3 }
            // n = 7, score = 200
            //   53                   | push                ebx
            //   53                   | push                ebx
            //   53                   | push                ebx
            //   53                   | push                ebx
            //   68????????           |                     
            //   ff560c               | call                dword ptr [esi + 0xc]
            //   3bc3                 | cmp                 eax, ebx

        $sequence_2 = { ff37 ffd3 832700 8b86401b0000 85c0 7403 50 }
            // n = 7, score = 200
            //   ff37                 | push                dword ptr [edi]
            //   ffd3                 | call                ebx
            //   832700               | and                 dword ptr [edi], 0
            //   8b86401b0000         | mov                 eax, dword ptr [esi + 0x1b40]
            //   85c0                 | test                eax, eax
            //   7403                 | je                  5
            //   50                   | push                eax

        $sequence_3 = { 56 8b742408 837e3400 742d }
            // n = 4, score = 200
            //   56                   | push                esi
            //   8b742408             | mov                 esi, dword ptr [esp + 8]
            //   837e3400             | cmp                 dword ptr [esi + 0x34], 0
            //   742d                 | je                  0x2f

        $sequence_4 = { 83f8ff 7458 8b4e18 66894102 897dfc }
            // n = 5, score = 200
            //   83f8ff               | cmp                 eax, -1
            //   7458                 | je                  0x5a
            //   8b4e18               | mov                 ecx, dword ptr [esi + 0x18]
            //   66894102             | mov                 word ptr [ecx + 2], ax
            //   897dfc               | mov                 dword ptr [ebp - 4], edi

        $sequence_5 = { 57 68???????? 50 ff5624 3bc3 894608 }
            // n = 6, score = 200
            //   57                   | push                edi
            //   68????????           |                     
            //   50                   | push                eax
            //   ff5624               | call                dword ptr [esi + 0x24]
            //   3bc3                 | cmp                 eax, ebx
            //   894608               | mov                 dword ptr [esi + 8], eax

        $sequence_6 = { 53 8d8558ffffff 50 8d86583c0000 50 e8???????? }
            // n = 6, score = 200
            //   53                   | push                ebx
            //   8d8558ffffff         | lea                 eax, [ebp - 0xa8]
            //   50                   | push                eax
            //   8d86583c0000         | lea                 eax, [esi + 0x3c58]
            //   50                   | push                eax
            //   e8????????           |                     

        $sequence_7 = { 74ee 48 0f85ec000000 8d85acfdffff 50 }
            // n = 5, score = 200
            //   74ee                 | je                  0xfffffff0
            //   48                   | dec                 eax
            //   0f85ec000000         | jne                 0xf2
            //   8d85acfdffff         | lea                 eax, [ebp - 0x254]
            //   50                   | push                eax

        $sequence_8 = { 897028 e8???????? 85c0 7549 56 e8???????? eb41 }
            // n = 7, score = 200
            //   897028               | mov                 dword ptr [eax + 0x28], esi
            //   e8????????           |                     
            //   85c0                 | test                eax, eax
            //   7549                 | jne                 0x4b
            //   56                   | push                esi
            //   e8????????           |                     
            //   eb41                 | jmp                 0x43

        $sequence_9 = { 741e 57 0fb74802 51 83c004 50 ff7640 }
            // n = 7, score = 200
            //   741e                 | je                  0x20
            //   57                   | push                edi
            //   0fb74802             | movzx               ecx, word ptr [eax + 2]
            //   51                   | push                ecx
            //   83c004               | add                 eax, 4
            //   50                   | push                eax
            //   ff7640               | push                dword ptr [esi + 0x40]

    condition:
        7 of them and filesize < 73728
}

rule win_computrace_w0 {
    meta:
        author = "ASERT"
        description = "Absolute Computrace Agent Executable"
        reference = "https://asert.arbornetworks.com/lojack-becomes-a-double-agent/#Yara"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.computrace"
        malpedia_version = "20180503"
        malpedia_sharing = "TLP:WHITE"
        malpedia_license = ""

    strings:
        $a = { D1 E0 F5 8B 4D 0C 83 D1 00 8B EC FF 33 83 C3 04 }
        $b1 = { 72 70 63 6E 65 74 70 2E 65 78 65 00 72 70 63 6E 65 74 70 00 }
        $b2 = { 54 61 67 49 64 00 }
    condition:
        $a or ($b1 and $b2)
}