rule win_computrace_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2020-12-22"
        version = "1"
        description = "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 = "20201222"
        malpedia_hash = "30354d830a29f0fbd3714d93d94dea941d77a130"
        malpedia_version = "20201023"
        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 = { e30d 83c00a 51 ff750c 50 }
            // n = 5, score = 200
            //   e30d                 | jecxz               0xf
            //   83c00a               | add                 eax, 0xa
            //   51                   | push                ecx
            //   ff750c               | push                dword ptr [ebp + 0xc]
            //   50                   | push                eax

        $sequence_1 = { ff15???????? 3de5030000 8b742410 7524 8b7c2414 }
            // n = 5, score = 200
            //   ff15????????         |                     
            //   3de5030000           | cmp                 eax, 0x3e5
            //   8b742410             | mov                 esi, dword ptr [esp + 0x10]
            //   7524                 | jne                 0x26
            //   8b7c2414             | mov                 edi, dword ptr [esp + 0x14]

        $sequence_2 = { 51 50 52 e8???????? 8b4630 85c0 7405 }
            // n = 7, score = 200
            //   51                   | push                ecx
            //   50                   | push                eax
            //   52                   | push                edx
            //   e8????????           |                     
            //   8b4630               | mov                 eax, dword ptr [esi + 0x30]
            //   85c0                 | test                eax, eax
            //   7405                 | je                  7

        $sequence_3 = { 85ff 7452 68???????? 8d45ac 50 8b1d???????? ffd3 }
            // n = 7, score = 200
            //   85ff                 | test                edi, edi
            //   7452                 | je                  0x54
            //   68????????           |                     
            //   8d45ac               | lea                 eax, [ebp - 0x54]
            //   50                   | push                eax
            //   8b1d????????         |                     
            //   ffd3                 | call                ebx

        $sequence_4 = { 03442404 c20400 8b4df0 64890d00000000 59 5f 5e }
            // n = 7, score = 200
            //   03442404             | add                 eax, dword ptr [esp + 4]
            //   c20400               | ret                 4
            //   8b4df0               | mov                 ecx, dword ptr [ebp - 0x10]
            //   64890d00000000       | mov                 dword ptr fs:[0], ecx
            //   59                   | pop                 ecx
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi

        $sequence_5 = { 85c0 748e e9???????? 6864440000 }
            // n = 4, score = 200
            //   85c0                 | test                eax, eax
            //   748e                 | je                  0xffffff90
            //   e9????????           |                     
            //   6864440000           | push                0x4464

        $sequence_6 = { 56 e8???????? 0fb64e18 c1e904 }
            // n = 4, score = 200
            //   56                   | push                esi
            //   e8????????           |                     
            //   0fb64e18             | movzx               ecx, byte ptr [esi + 0x18]
            //   c1e904               | shr                 ecx, 4

        $sequence_7 = { e8???????? 8b7d10 895df8 eb64 3b1e 7506 3bdf }
            // n = 7, score = 200
            //   e8????????           |                     
            //   8b7d10               | mov                 edi, dword ptr [ebp + 0x10]
            //   895df8               | mov                 dword ptr [ebp - 8], ebx
            //   eb64                 | jmp                 0x66
            //   3b1e                 | cmp                 ebx, dword ptr [esi]
            //   7506                 | jne                 8
            //   3bdf                 | cmp                 ebx, edi

        $sequence_8 = { 85f6 740f 56 ff74240c e8???????? 8d460c eb02 }
            // n = 7, score = 200
            //   85f6                 | test                esi, esi
            //   740f                 | je                  0x11
            //   56                   | push                esi
            //   ff74240c             | push                dword ptr [esp + 0xc]
            //   e8????????           |                     
            //   8d460c               | lea                 eax, [esi + 0xc]
            //   eb02                 | jmp                 4

        $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:
        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)
}