rule win_dispenserxfs_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.dispenserxfs."
        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.dispenserxfs"
        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 = { 8d45ec 50 53 8d45d4 50 6837010000 57 }
            // n = 7, score = 200
            //   8d45ec               | lea                 eax, [ebp - 0x14]
            //   50                   | push                eax
            //   53                   | push                ebx
            //   8d45d4               | lea                 eax, [ebp - 0x2c]
            //   50                   | push                eax
            //   6837010000           | push                0x137
            //   57                   | push                edi

        $sequence_1 = { 56 57 8bf2 bf???????? e8???????? }
            // n = 5, score = 200
            //   56                   | push                esi
            //   57                   | push                edi
            //   8bf2                 | mov                 esi, edx
            //   bf????????           |                     
            //   e8????????           |                     

        $sequence_2 = { 837d0800 750b 8b4c2408 e8???????? eb66 837d0801 }
            // n = 6, score = 200
            //   837d0800             | cmp                 dword ptr [ebp + 8], 0
            //   750b                 | jne                 0xd
            //   8b4c2408             | mov                 ecx, dword ptr [esp + 8]
            //   e8????????           |                     
            //   eb66                 | jmp                 0x68
            //   837d0801             | cmp                 dword ptr [ebp + 8], 1

        $sequence_3 = { 7e0e 6683380a 7501 4a 83e802 3bc7 }
            // n = 6, score = 200
            //   7e0e                 | jle                 0x10
            //   6683380a             | cmp                 word ptr [eax], 0xa
            //   7501                 | jne                 3
            //   4a                   | dec                 edx
            //   83e802               | sub                 eax, 2
            //   3bc7                 | cmp                 eax, edi

        $sequence_4 = { ff750c 6800100000 53 ff75fc ffd0 5b 8be5 }
            // n = 7, score = 200
            //   ff750c               | push                dword ptr [ebp + 0xc]
            //   6800100000           | push                0x1000
            //   53                   | push                ebx
            //   ff75fc               | push                dword ptr [ebp - 4]
            //   ffd0                 | call                eax
            //   5b                   | pop                 ebx
            //   8be5                 | mov                 esp, ebp

        $sequence_5 = { 663bc6 75f5 6810200000 2bca 8d442414 50 d1f9 }
            // n = 7, score = 200
            //   663bc6               | cmp                 ax, si
            //   75f5                 | jne                 0xfffffff7
            //   6810200000           | push                0x2010
            //   2bca                 | sub                 ecx, edx
            //   8d442414             | lea                 eax, [esp + 0x14]
            //   50                   | push                eax
            //   d1f9                 | sar                 ecx, 1

        $sequence_6 = { ba???????? 8bce e8???????? a3???????? 6a00 6a02 }
            // n = 6, score = 200
            //   ba????????           |                     
            //   8bce                 | mov                 ecx, esi
            //   e8????????           |                     
            //   a3????????           |                     
            //   6a00                 | push                0
            //   6a02                 | push                2

        $sequence_7 = { ff15???????? 2b45fc 3de0930400 774a 68???????? e8???????? }
            // n = 6, score = 200
            //   ff15????????         |                     
            //   2b45fc               | sub                 eax, dword ptr [ebp - 4]
            //   3de0930400           | cmp                 eax, 0x493e0
            //   774a                 | ja                  0x4c
            //   68????????           |                     
            //   e8????????           |                     

        $sequence_8 = { 0fb74802 6685c9 0f84c9000000 8b5004 }
            // n = 4, score = 200
            //   0fb74802             | movzx               ecx, word ptr [eax + 2]
            //   6685c9               | test                cx, cx
            //   0f84c9000000         | je                  0xcf
            //   8b5004               | mov                 edx, dword ptr [eax + 4]

        $sequence_9 = { 6838010000 57 ff15???????? 5e 85c0 7516 68???????? }
            // n = 7, score = 200
            //   6838010000           | push                0x138
            //   57                   | push                edi
            //   ff15????????         |                     
            //   5e                   | pop                 esi
            //   85c0                 | test                eax, eax
            //   7516                 | jne                 0x18
            //   68????????           |                     

    condition:
        7 of them and filesize < 114688
}

import "pe"

rule win_dispenserxfs_w0 {
    meta:
        description = "Detects ATM Malware DispenserXFS"
        author = "@Xylit0l @r3c0nst / Modified by Florian Roth"
        reference = "https://twitter.com/r3c0nst/status/1100775857306652673"
        date = "2019/02/27"
        score = 80
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.dispenserxfs"
        malpedia_version = "20190307"
        malpedia_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"

    strings:
        $xc1 = { 68 FF FF 00 00 68 60 EA 00 00 6A 10 }
        $s1 = "\\dispenserXFS.pdb" ascii wide
        $s3 = "C:\\xfsasdf.txt" fullword ascii
        $s4 = "Injected mxsfs killer into %d." fullword ascii
        $s5 = "Waiting for freeze msxfs processes..." fullword ascii

    condition:
        1 of them or pe.imphash() == "617e037ae26d1931818db0790fb44bfe"
}