rule win_computrace_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2020-10-14"
        version = "1"
        description = "autogenerated rule brought to you by yara-signator"
        tool = "yara-signator v0.5.0"
        tool_config = "callsandjumps;datarefs;binvalue"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.computrace"
        malpedia_rule_date = "20201014"
        malpedia_hash = "a7e3bd57eaf12bf3ea29a863c041091ba3af9ac9"
        malpedia_version = "20201014"
        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 = { 8b74240c 56 8d5e78 e8???????? 8b86983b0000 }
            // n = 5, score = 200
            //   8b74240c             | mov                 esi, dword ptr [esp + 0xc]
            //   56                   | push                esi
            //   8d5e78               | lea                 ebx, [esi + 0x78]
            //   e8????????           |                     
            //   8b86983b0000         | mov                 eax, dword ptr [esi + 0x3b98]

        $sequence_1 = { 751d ff761c ff7618 56 e8???????? }
            // n = 5, score = 200
            //   751d                 | jne                 0x1f
            //   ff761c               | push                dword ptr [esi + 0x1c]
            //   ff7618               | push                dword ptr [esi + 0x18]
            //   56                   | push                esi
            //   e8????????           |                     

        $sequence_2 = { 57 8d7710 e8???????? 8bc7 2b87481b0000 56 8906 }
            // n = 7, score = 200
            //   57                   | push                edi
            //   8d7710               | lea                 esi, [edi + 0x10]
            //   e8????????           |                     
            //   8bc7                 | mov                 eax, edi
            //   2b87481b0000         | sub                 eax, dword ptr [edi + 0x1b48]
            //   56                   | push                esi
            //   8906                 | mov                 dword ptr [esi], eax

        $sequence_3 = { b904000000 83ec02 6651 50 56 ff5628 eb06 }
            // n = 7, score = 200
            //   b904000000           | mov                 ecx, 4
            //   83ec02               | sub                 esp, 2
            //   6651                 | push                cx
            //   50                   | push                eax
            //   56                   | push                esi
            //   ff5628               | call                dword ptr [esi + 0x28]
            //   eb06                 | jmp                 8

        $sequence_4 = { 890f c7470414000000 ff30 ff15???????? f7d8 1bc0 40 }
            // n = 7, score = 200
            //   890f                 | mov                 dword ptr [edi], ecx
            //   c7470414000000       | mov                 dword ptr [edi + 4], 0x14
            //   ff30                 | push                dword ptr [eax]
            //   ff15????????         |                     
            //   f7d8                 | neg                 eax
            //   1bc0                 | sbb                 eax, eax
            //   40                   | inc                 eax

        $sequence_5 = { e8???????? 89869c3b0000 5f 8b8e983b0000 8a843158390000 }
            // n = 5, score = 200
            //   e8????????           |                     
            //   89869c3b0000         | mov                 dword ptr [esi + 0x3b9c], eax
            //   5f                   | pop                 edi
            //   8b8e983b0000         | mov                 ecx, dword ptr [esi + 0x3b98]
            //   8a843158390000       | mov                 al, byte ptr [ecx + esi + 0x3958]

        $sequence_6 = { 50 57 8d86c81b0000 50 }
            // n = 4, score = 200
            //   50                   | push                eax
            //   57                   | push                edi
            //   8d86c81b0000         | lea                 eax, [esi + 0x1bc8]
            //   50                   | push                eax

        $sequence_7 = { 8a4701 f08605???????? 3a4701 0f924701 8bf7 }
            // n = 5, score = 200
            //   8a4701               | mov                 al, byte ptr [edi + 1]
            //   f08605????????       |                     
            //   3a4701               | cmp                 al, byte ptr [edi + 1]
            //   0f924701             | setb                byte ptr [edi + 1]
            //   8bf7                 | mov                 esi, edi

        $sequence_8 = { 8b8658440000 3b45e8 741f 8d45e0 50 ff15???????? 8d45e0 }
            // n = 7, score = 200
            //   8b8658440000         | mov                 eax, dword ptr [esi + 0x4458]
            //   3b45e8               | cmp                 eax, dword ptr [ebp - 0x18]
            //   741f                 | je                  0x21
            //   8d45e0               | lea                 eax, [ebp - 0x20]
            //   50                   | push                eax
            //   ff15????????         |                     
            //   8d45e0               | lea                 eax, [ebp - 0x20]

        $sequence_9 = { 6a00 51 50 56 e8???????? 03f8 53 }
            // n = 7, score = 200
            //   6a00                 | push                0
            //   51                   | push                ecx
            //   50                   | push                eax
            //   56                   | push                esi
            //   e8????????           |                     
            //   03f8                 | add                 edi, eax
            //   53                   | push                ebx

    condition:
        7 of them and filesize < 73728
}

rule win_computrace_w0 {
    meta:
        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_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"

    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)
}