SYMBOLCOMMON_NAMEaka. SYNONYMS
win.kagent (Back to overview)

KAgent

Actor(s): Cleaver


There is no description at this point.

References
2016-04-06CylanceCylance
@techreport{cylance:20160406:operation:d4da7b5, author = {Cylance}, title = {{Operation Cleaver}}, date = {2016-04-06}, institution = {Cylance}, url = {https://www.cylance.com/content/dam/cylance/pages/operation-cleaver/Cylance_Operation_Cleaver_Report.pdf}, language = {English}, urldate = {2020-01-10} } Operation Cleaver
CsExt Jasus KAgent NetC PvzOut SynFlooder TinyZbot WndTest ZhCat ZhMimikatz Cleaver
Yara Rules
[TLP:WHITE] win_kagent_auto (20221125 | Detects win.kagent.)
rule win_kagent_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-11-21"
        version = "1"
        description = "Detects win.kagent."
        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.kagent"
        malpedia_rule_date = "20221118"
        malpedia_hash = "e0702e2e6d1d00da65c8a29a4ebacd0a4c59e1af"
        malpedia_version = "20221125"
        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 = { ff75f8 ffd0 817d0c11010000 0f85cf000000 0fb74510 3bc3 7518 }
            // n = 7, score = 400
            //   ff75f8               | push                dword ptr [ebp - 8]
            //   ffd0                 | call                eax
            //   817d0c11010000       | cmp                 dword ptr [ebp + 0xc], 0x111
            //   0f85cf000000         | jne                 0xd5
            //   0fb74510             | movzx               eax, word ptr [ebp + 0x10]
            //   3bc3                 | cmp                 eax, ebx
            //   7518                 | jne                 0x1a

        $sequence_1 = { 393c98 7503 6a20 5b 53 }
            // n = 5, score = 400
            //   393c98               | cmp                 dword ptr [eax + ebx*4], edi
            //   7503                 | jne                 5
            //   6a20                 | push                0x20
            //   5b                   | pop                 ebx
            //   53                   | push                ebx

        $sequence_2 = { 8b4508 50 e8???????? c3 8d4de8 e9???????? }
            // n = 6, score = 400
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   50                   | push                eax
            //   e8????????           |                     
            //   c3                   | ret                 
            //   8d4de8               | lea                 ecx, [ebp - 0x18]
            //   e9????????           |                     

        $sequence_3 = { ff36 e8???????? 85c0 750c 81c618040000 85ff 75e0 }
            // n = 7, score = 400
            //   ff36                 | push                dword ptr [esi]
            //   e8????????           |                     
            //   85c0                 | test                eax, eax
            //   750c                 | jne                 0xe
            //   81c618040000         | add                 esi, 0x418
            //   85ff                 | test                edi, edi
            //   75e0                 | jne                 0xffffffe2

        $sequence_4 = { c1fa05 8bc8 83e11f c1e106 030c95007b4200 eb05 b9???????? }
            // n = 7, score = 400
            //   c1fa05               | sar                 edx, 5
            //   8bc8                 | mov                 ecx, eax
            //   83e11f               | and                 ecx, 0x1f
            //   c1e106               | shl                 ecx, 6
            //   030c95007b4200       | add                 ecx, dword ptr [edx*4 + 0x427b00]
            //   eb05                 | jmp                 7
            //   b9????????           |                     

        $sequence_5 = { ff15???????? 8d85e4fdffff 50 ff15???????? 8b35???????? 8d8da0fbffff 51 }
            // n = 7, score = 400
            //   ff15????????         |                     
            //   8d85e4fdffff         | lea                 eax, [ebp - 0x21c]
            //   50                   | push                eax
            //   ff15????????         |                     
            //   8b35????????         |                     
            //   8d8da0fbffff         | lea                 ecx, [ebp - 0x460]
            //   51                   | push                ecx

        $sequence_6 = { e8???????? 8b4510 8b4d0c 50 51 53 }
            // n = 6, score = 400
            //   e8????????           |                     
            //   8b4510               | mov                 eax, dword ptr [ebp + 0x10]
            //   8b4d0c               | mov                 ecx, dword ptr [ebp + 0xc]
            //   50                   | push                eax
            //   51                   | push                ecx
            //   53                   | push                ebx

        $sequence_7 = { 53 50 6851010000 ff75f8 ffd6 43 83fb21 }
            // n = 7, score = 400
            //   53                   | push                ebx
            //   50                   | push                eax
            //   6851010000           | push                0x151
            //   ff75f8               | push                dword ptr [ebp - 8]
            //   ffd6                 | call                esi
            //   43                   | inc                 ebx
            //   83fb21               | cmp                 ebx, 0x21

        $sequence_8 = { 85db 7e1d 8bd0 2bd6 }
            // n = 4, score = 400
            //   85db                 | test                ebx, ebx
            //   7e1d                 | jle                 0x1f
            //   8bd0                 | mov                 edx, eax
            //   2bd6                 | sub                 edx, esi

        $sequence_9 = { c645fc05 888bbc000000 0f90c1 f7d9 0bc8 51 e8???????? }
            // n = 7, score = 400
            //   c645fc05             | mov                 byte ptr [ebp - 4], 5
            //   888bbc000000         | mov                 byte ptr [ebx + 0xbc], cl
            //   0f90c1               | seto                cl
            //   f7d9                 | neg                 ecx
            //   0bc8                 | or                  ecx, eax
            //   51                   | push                ecx
            //   e8????????           |                     

    condition:
        7 of them and filesize < 4972544
}
[TLP:WHITE] win_kagent_w0   (20170521 | Backdoor used by attackers in Operation Cleaver)
rule win_kagent_w0 {
	meta:
		description = "Backdoor used by attackers in Operation Cleaver"
		reference = "http://cylance.com/assets/Cleaver/Cylance_Operation_Cleaver_Report.pdf"
		date = "2014/12/02"
		author = "Cylance Inc."
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.kagent"
        malpedia_version = "20170521"
        malpedia_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"
	strings:
		$s1 = "kill command is in last machine, going back"
		$s2 = "message data length in B64: %d Bytes"
	condition:
		all of them
}
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