SYMBOLCOMMON_NAMEaka. SYNONYMS
win.jasus (Back to overview)

Jasus

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_jasus_auto (20220516 | Detects win.jasus.)
rule win_jasus_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-05-16"
        version = "1"
        description = "Detects win.jasus."
        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.jasus"
        malpedia_rule_date = "20220513"
        malpedia_hash = "7f4b2229e6ae614d86d74917f6d5b41890e62a26"
        malpedia_version = "20220516"
        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 = { 83f8ff 7516 8d85e0fdffff 6a00 50 e8???????? }
            // n = 6, score = 200
            //   83f8ff               | cmp                 eax, -1
            //   7516                 | jne                 0x18
            //   8d85e0fdffff         | lea                 eax, [ebp - 0x220]
            //   6a00                 | push                0
            //   50                   | push                eax
            //   e8????????           |                     

        $sequence_1 = { 894604 81e1ff000000 c1ef08 333c8da0ca4100 8b4c2418 }
            // n = 5, score = 200
            //   894604               | mov                 dword ptr [esi + 4], eax
            //   81e1ff000000         | and                 ecx, 0xff
            //   c1ef08               | shr                 edi, 8
            //   333c8da0ca4100       | xor                 edi, dword ptr [ecx*4 + 0x41caa0]
            //   8b4c2418             | mov                 ecx, dword ptr [esp + 0x18]

        $sequence_2 = { 7d08 8b10 894dfc 8955f8 83c028 41 }
            // n = 6, score = 200
            //   7d08                 | jge                 0xa
            //   8b10                 | mov                 edx, dword ptr [eax]
            //   894dfc               | mov                 dword ptr [ebp - 4], ecx
            //   8955f8               | mov                 dword ptr [ebp - 8], edx
            //   83c028               | add                 eax, 0x28
            //   41                   | inc                 ecx

        $sequence_3 = { ff06 8b4e20 8b4624 8b16 3bc8 7419 3bc2 }
            // n = 7, score = 200
            //   ff06                 | inc                 dword ptr [esi]
            //   8b4e20               | mov                 ecx, dword ptr [esi + 0x20]
            //   8b4624               | mov                 eax, dword ptr [esi + 0x24]
            //   8b16                 | mov                 edx, dword ptr [esi]
            //   3bc8                 | cmp                 ecx, eax
            //   7419                 | je                  0x1b
            //   3bc2                 | cmp                 eax, edx

        $sequence_4 = { 7c08 8d50f6 83fa06 7704 b101 eb02 32c9 }
            // n = 7, score = 200
            //   7c08                 | jl                  0xa
            //   8d50f6               | lea                 edx, [eax - 0xa]
            //   83fa06               | cmp                 edx, 6
            //   7704                 | ja                  6
            //   b101                 | mov                 cl, 1
            //   eb02                 | jmp                 4
            //   32c9                 | xor                 cl, cl

        $sequence_5 = { 81e7ff000000 c1e808 3304bda0ca4100 0fb67902 33f8 81e7ff000000 c1e808 }
            // n = 7, score = 200
            //   81e7ff000000         | and                 edi, 0xff
            //   c1e808               | shr                 eax, 8
            //   3304bda0ca4100       | xor                 eax, dword ptr [edi*4 + 0x41caa0]
            //   0fb67902             | movzx               edi, byte ptr [ecx + 2]
            //   33f8                 | xor                 edi, eax
            //   81e7ff000000         | and                 edi, 0xff
            //   c1e808               | shr                 eax, 8

        $sequence_6 = { 750a 80fb2b 7405 80fb2f 757d }
            // n = 5, score = 200
            //   750a                 | jne                 0xc
            //   80fb2b               | cmp                 bl, 0x2b
            //   7405                 | je                  7
            //   80fb2f               | cmp                 bl, 0x2f
            //   757d                 | jne                 0x7f

        $sequence_7 = { 8b02 57 50 68???????? e8???????? 83c040 }
            // n = 6, score = 200
            //   8b02                 | mov                 eax, dword ptr [edx]
            //   57                   | push                edi
            //   50                   | push                eax
            //   68????????           |                     
            //   e8????????           |                     
            //   83c040               | add                 eax, 0x40

        $sequence_8 = { e8???????? 8be5 5d c3 8b5016 8b4dac 8911 }
            // n = 7, score = 200
            //   e8????????           |                     
            //   8be5                 | mov                 esp, ebp
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   8b5016               | mov                 edx, dword ptr [eax + 0x16]
            //   8b4dac               | mov                 ecx, dword ptr [ebp - 0x54]
            //   8911                 | mov                 dword ptr [ecx], edx

        $sequence_9 = { 894ddc 895dd6 668945da ff15???????? 8b0d???????? 8b55b0 668945d4 }
            // n = 7, score = 200
            //   894ddc               | mov                 dword ptr [ebp - 0x24], ecx
            //   895dd6               | mov                 dword ptr [ebp - 0x2a], ebx
            //   668945da             | mov                 word ptr [ebp - 0x26], ax
            //   ff15????????         |                     
            //   8b0d????????         |                     
            //   8b55b0               | mov                 edx, dword ptr [ebp - 0x50]
            //   668945d4             | mov                 word ptr [ebp - 0x2c], ax

    condition:
        7 of them and filesize < 507904
}
[TLP:WHITE] win_jasus_w0   (20170521 | ARP cache poisoner used by attackers in Operation Cleaver)
rule win_jasus_w0 {
	meta:
		description = "ARP cache poisoner 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.jasus"
        malpedia_version = "20170521"
        malpedia_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"
	strings:
		$s1 = "pcap_dump_open"
		$s2 = "Resolving IPs to poison..."
		$s3 = "WARNNING: Gateway IP can not be found"
	condition:
		all of them
}
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