rule win_infy_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        version = "1"
        description = "Detects win.infy."
        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.infy"
        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 = { 7e24 8945d4 807de300 7409 8b45e4 66833820 }
            // n = 6, score = 200
            //   7e24                 | jle                 0x26
            //   8945d4               | mov                 dword ptr [ebp - 0x2c], eax
            //   807de300             | cmp                 byte ptr [ebp - 0x1d], 0
            //   7409                 | je                  0xb
            //   8b45e4               | mov                 eax, dword ptr [ebp - 0x1c]
            //   66833820             | cmp                 word ptr [eax], 0x20

        $sequence_1 = { 85c9 7432 668379f602 741f 89c6 8b449504 e8???????? }
            // n = 7, score = 200
            //   85c9                 | test                ecx, ecx
            //   7432                 | je                  0x34
            //   668379f602           | cmp                 word ptr [ecx - 0xa], 2
            //   741f                 | je                  0x21
            //   89c6                 | mov                 esi, eax
            //   8b449504             | mov                 eax, dword ptr [ebp + edx*4 + 4]
            //   e8????????           |                     

        $sequence_2 = { 8bec 0fb64d0c 8b4508 8b5510 }
            // n = 4, score = 200
            //   8bec                 | mov                 ebp, esp
            //   0fb64d0c             | movzx               ecx, byte ptr [ebp + 0xc]
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   8b5510               | mov                 edx, dword ptr [ebp + 0x10]

        $sequence_3 = { 668379f602 7424 89c6 8955fc 8b449504 e8???????? 8b55fc }
            // n = 7, score = 200
            //   668379f602           | cmp                 word ptr [ecx - 0xa], 2
            //   7424                 | je                  0x26
            //   89c6                 | mov                 esi, eax
            //   8955fc               | mov                 dword ptr [ebp - 4], edx
            //   8b449504             | mov                 eax, dword ptr [ebp + edx*4 + 4]
            //   e8????????           |                     
            //   8b55fc               | mov                 edx, dword ptr [ebp - 4]

        $sequence_4 = { 83fbff 7474 6a00 53 }
            // n = 4, score = 200
            //   83fbff               | cmp                 ebx, -1
            //   7474                 | je                  0x76
            //   6a00                 | push                0
            //   53                   | push                ebx

        $sequence_5 = { 8b5d08 53 e8???????? 59 c1e002 }
            // n = 5, score = 200
            //   8b5d08               | mov                 ebx, dword ptr [ebp + 8]
            //   53                   | push                ebx
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   c1e002               | shl                 eax, 2

        $sequence_6 = { 83c408 8945fc 8b45fc c1e002 034610 f6400380 0f94c2 }
            // n = 7, score = 200
            //   83c408               | add                 esp, 8
            //   8945fc               | mov                 dword ptr [ebp - 4], eax
            //   8b45fc               | mov                 eax, dword ptr [ebp - 4]
            //   c1e002               | shl                 eax, 2
            //   034610               | add                 eax, dword ptr [esi + 0x10]
            //   f6400380             | test                byte ptr [eax + 3], 0x80
            //   0f94c2               | sete                dl

        $sequence_7 = { 8d4620 0fb74b02 8d1401 895308 }
            // n = 4, score = 200
            //   8d4620               | lea                 eax, [esi + 0x20]
            //   0fb74b02             | movzx               ecx, word ptr [ebx + 2]
            //   8d1401               | lea                 edx, [ecx + eax]
            //   895308               | mov                 dword ptr [ebx + 8], edx

        $sequence_8 = { 8bd8 85db 750c 8b45f0 }
            // n = 4, score = 200
            //   8bd8                 | mov                 ebx, eax
            //   85db                 | test                ebx, ebx
            //   750c                 | jne                 0xe
            //   8b45f0               | mov                 eax, dword ptr [ebp - 0x10]

        $sequence_9 = { 0fb74af4 870c24 51 8b4afc e9???????? }
            // n = 5, score = 200
            //   0fb74af4             | movzx               ecx, word ptr [edx - 0xc]
            //   870c24               | xchg                dword ptr [esp], ecx
            //   51                   | push                ecx
            //   8b4afc               | mov                 ecx, dword ptr [edx - 4]
            //   e9????????           |                     

    condition:
        7 of them and filesize < 147456
}

rule win_infy_w0 {
    meta:
        author = "Florian Roth"
        description = "Detects Foudre Backdoor"
        info = "foudre dropper"
        reference = "https://goo.gl/Nbqbt6"
        date = "2017-08-01"
        hash = "7e73a727dc8f3c48e58468c3fd0a193a027d085f25fa274a6e187cf503f01f74"
        hash = "7ce2c5111e3560aa6036f98b48ceafe83aa1ac3d3b33392835316c859970f8bc"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.infy"
        malpedia_version = "20170803"
        malpedia_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"
    strings:
        $s1 = "initialization failed: Reinstall the program" fullword wide
        $s2 = "SnailDriver V1" fullword wide
        $s3 = "lp.ini" fullword wide
    condition:
        filesize < 100KB and 2 of them
}

rule win_infy_w1 {
    meta:
        author = "Florian Roth"
        description = "Detects Foudre Backdoor"
        info = "foudre dropper 2"
        reference = "https://goo.gl/Nbqbt6"
        date = "2017-08-01"
        hash = "6bc9f6ac2f6688ed63baa29913eaf8c64738cf19933d974d25a0c26b7d01b9ac"
        hash = "da228831089c56743d1fbc8ef156c672017cdf46a322d847a270b9907def53a5"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.infy"
        malpedia_version = "20170803"
        malpedia_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"
    strings:
        $x1 = "536F594A96C5496CB3949A4DA4775B576E049C57696E646F77735C43757272656E7456657273696F6E5C5C52756E" fullword wide
        $x2 = "2220263024C380B3278695851482EC32" fullword wide

        $s1 = "C:\\Documents and Settings\\All Users\\Start Menu\\Programs\\\\Startup\\" fullword wide
        $s2 = "C:\\Documents and Settings\\All Users\\" fullword wide
        $s3 = "Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\\\Shell Folders" fullword wide
        $s4 = "ShellExecuteW" fullword wide
    condition:
        filesize < 100KB and ( 1 of ($x*) or 4 of them ) 
}

import "pe"

rule win_infy_w2 {
    meta:
        description = "Detects Foudre Backdoor"
        author = "Florian Roth"
        info = "foudre backdoor"
        reference = "https://goo.gl/Nbqbt6"
        date = "2017-08-01"
        hash = "7c6206eaf0c5c9c6c8d8586a626b49575942572c51458575e51cba72ba2096a4"
        hash = "db605d501d3a5ca2b0e3d8296d552fbbf048ee831be21efca407c45bf794b109"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.infy"
        malpedia_version = "20170803"
        malpedia_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"
    strings:
        /* $s1 = "Project1.dll" fullword ascii */
        /* Better: Project1.dll\x00D1 */
        $s1 = { 50 72 6F 6A 65 63 74 31 2E 64 6C 6C 00 44 31 }
        $s2 = "winmgmts:\\\\localhost\\root\\SecurityCenter2" fullword wide
        $s3 = "C:\\Documents and Settings\\All Users\\" fullword wide
    condition:
        filesize < 2000KB and 3 of them or (2 of them and pe.exports("D1"))
}