SYMBOLCOMMON_NAMEaka. SYNONYMS
win.pkybot (Back to overview)

Pkybot

aka: Pykbot, TBag, Bublik
URLhaus    

Pkybot is a trojan, which has its roots as a downloader dubbed Bublik in 2013 and was seen distributing GameoverZeus in 2014 (ref: fortinet). In the beginning of 2015, webinject capability was added according to /Kleissner/Kafeine/iSight using the infamous ATS.

References
2015-06-10Kleissner & AssociatesPeter Kleissner
@online{kleissner:20150610:pony:2dbaf47, author = {Peter Kleissner}, title = {{Pony + Pkybot + Automated Transfer System = Banker}}, date = {2015-06-10}, organization = {Kleissner & Associates}, url = {http://blog.kleissner.org/?p=788}, language = {English}, urldate = {2020-01-08} } Pony + Pkybot + Automated Transfer System = Banker
Pkybot
Yara Rules
[TLP:WHITE] win_pkybot_auto (20230125 | Detects win.pkybot.)
rule win_pkybot_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-01-25"
        version = "1"
        description = "Detects win.pkybot."
        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.pkybot"
        malpedia_rule_date = "20230124"
        malpedia_hash = "2ee0eebba83dce3d019a90519f2f972c0fcf9686"
        malpedia_version = "20230125"
        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 = { e8???????? 83c40c 84c0 7509 8bde 8b761c }
            // n = 6, score = 1400
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   84c0                 | test                al, al
            //   7509                 | jne                 0xb
            //   8bde                 | mov                 ebx, esi
            //   8b761c               | mov                 esi, dword ptr [esi + 0x1c]

        $sequence_1 = { 837e0400 59 59 75dc 832600 }
            // n = 5, score = 1400
            //   837e0400             | cmp                 dword ptr [esi + 4], 0
            //   59                   | pop                 ecx
            //   59                   | pop                 ecx
            //   75dc                 | jne                 0xffffffde
            //   832600               | and                 dword ptr [esi], 0

        $sequence_2 = { ff5008 6a34 e8???????? 59 85c0 740c }
            // n = 6, score = 1400
            //   ff5008               | call                dword ptr [eax + 8]
            //   6a34                 | push                0x34
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   85c0                 | test                eax, eax
            //   740c                 | je                  0xe

        $sequence_3 = { 8d459c 6a02 50 e8???????? }
            // n = 4, score = 1400
            //   8d459c               | lea                 eax, [ebp - 0x64]
            //   6a02                 | push                2
            //   50                   | push                eax
            //   e8????????           |                     

        $sequence_4 = { e8???????? 8d8edc000000 e8???????? 8d8e28010000 }
            // n = 4, score = 1400
            //   e8????????           |                     
            //   8d8edc000000         | lea                 ecx, [esi + 0xdc]
            //   e8????????           |                     
            //   8d8e28010000         | lea                 ecx, [esi + 0x128]

        $sequence_5 = { 7411 8b4e18 8b01 ff5008 }
            // n = 4, score = 1400
            //   7411                 | je                  0x13
            //   8b4e18               | mov                 ecx, dword ptr [esi + 0x18]
            //   8b01                 | mov                 eax, dword ptr [ecx]
            //   ff5008               | call                dword ptr [eax + 8]

        $sequence_6 = { 53 56 57 6a10 ff7510 }
            // n = 5, score = 1400
            //   53                   | push                ebx
            //   56                   | push                esi
            //   57                   | push                edi
            //   6a10                 | push                0x10
            //   ff7510               | push                dword ptr [ebp + 0x10]

        $sequence_7 = { 74e6 6a10 8d45f0 50 56 ff15???????? }
            // n = 6, score = 1400
            //   74e6                 | je                  0xffffffe8
            //   6a10                 | push                0x10
            //   8d45f0               | lea                 eax, [ebp - 0x10]
            //   50                   | push                eax
            //   56                   | push                esi
            //   ff15????????         |                     

        $sequence_8 = { ff75f8 ff15???????? 85c0 756a ff15???????? 83f87a }
            // n = 6, score = 1400
            //   ff75f8               | push                dword ptr [ebp - 8]
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   756a                 | jne                 0x6c
            //   ff15????????         |                     
            //   83f87a               | cmp                 eax, 0x7a

        $sequence_9 = { 50 894608 e8???????? 6a05 50 }
            // n = 5, score = 1400
            //   50                   | push                eax
            //   894608               | mov                 dword ptr [esi + 8], eax
            //   e8????????           |                     
            //   6a05                 | push                5
            //   50                   | push                eax

    condition:
        7 of them and filesize < 204800
}
Download all Yara Rules