SYMBOLCOMMON_NAMEaka. SYNONYMS
win.eyservice (Back to overview)

EYService

Actor(s): Nazar


EYService is the main part of the backdoor used by Nazar APT. This a passive backdoor that relies on, now discontinued, Packet Sniffer SDK (PSSDK) from Microolap.

References
2020-05-05CheckpointCheck Point Research
@online{research:20200505:nazar:a4d2c7c, author = {Check Point Research}, title = {{Nazar: Spirits of the Past}}, date = {2020-05-05}, organization = {Checkpoint}, url = {https://research.checkpoint.com/2020/nazar-spirits-of-the-past/}, language = {English}, urldate = {2020-05-05} } Nazar: Spirits of the Past
EYService
2020-04-27MalwareLab.plMaciej Kotowicz
@online{kotowicz:20200427:quick:e6bf310, author = {Maciej Kotowicz}, title = {{Quick look at Nazar's backdoor - Network Communication}}, date = {2020-04-27}, organization = {MalwareLab.pl}, url = {https://blog.malwarelab.pl/posts/nazar_eyservice_comm/}, language = {English}, urldate = {2020-05-05} } Quick look at Nazar's backdoor - Network Communication
EYService
2020-04-23MalwareLab.plMaciej Kotowicz
@online{kotowicz:20200423:quick:ce2218e, author = {Maciej Kotowicz}, title = {{Quick look at Nazar backdoor - Capabilities}}, date = {2020-04-23}, organization = {MalwareLab.pl}, url = {https://blog.malwarelab.pl/posts/nazar_eyservice/}, language = {English}, urldate = {2020-05-05} } Quick look at Nazar backdoor - Capabilities
EYService
2020-04-22EpicTurlaJuan Andrés Guerrero-Saade
@online{guerrerosaade:20200422:nazar:0c5eef8, author = {Juan Andrés Guerrero-Saade}, title = {{Nazar: A Lost Amulet}}, date = {2020-04-22}, organization = {EpicTurla}, url = {https://www.epicturla.com/blog/the-lost-nazar}, language = {English}, urldate = {2020-05-05} } Nazar: A Lost Amulet
EYService Nazar
2018-03CrySyS LabBoldizsar Bencsath
@techreport{bencsath:201803:territorial:04343bb, author = {Boldizsar Bencsath}, title = {{Territorial Dispute – NSA’s perspective on APT landscape}}, date = {2018-03}, institution = {CrySyS Lab}, url = {https://www.crysys.hu/publications/files/tedi/ukatemicrysys_territorialdispute.pdf}, language = {English}, urldate = {2020-05-07} } Territorial Dispute – NSA’s perspective on APT landscape
9002 RAT Agent.BTZ DuQu EYService Flame FlowerShop Stuxnet Uroburos
Yara Rules
[TLP:WHITE] win_eyservice_auto (20230125 | Detects win.eyservice.)
rule win_eyservice_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-01-25"
        version = "1"
        description = "Detects win.eyservice."
        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.eyservice"
        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???????? 8b4608 8b4e04 8b16 8b5220 50 51 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   8b4608               | mov                 eax, dword ptr [esi + 8]
            //   8b4e04               | mov                 ecx, dword ptr [esi + 4]
            //   8b16                 | mov                 edx, dword ptr [esi]
            //   8b5220               | mov                 edx, dword ptr [edx + 0x20]
            //   50                   | push                eax
            //   51                   | push                ecx

        $sequence_1 = { b800200000 8b16 8b521c 50 8b4628 8b4804 03cb }
            // n = 7, score = 100
            //   b800200000           | mov                 eax, 0x2000
            //   8b16                 | mov                 edx, dword ptr [esi]
            //   8b521c               | mov                 edx, dword ptr [edx + 0x1c]
            //   50                   | push                eax
            //   8b4628               | mov                 eax, dword ptr [esi + 0x28]
            //   8b4804               | mov                 ecx, dword ptr [eax + 4]
            //   03cb                 | add                 ecx, ebx

        $sequence_2 = { 8d4c2462 03d0 68???????? 51 c68414930000003b }
            // n = 5, score = 100
            //   8d4c2462             | lea                 ecx, [esp + 0x62]
            //   03d0                 | add                 edx, eax
            //   68????????           |                     
            //   51                   | push                ecx
            //   c68414930000003b     | mov                 byte ptr [esp + edx + 0x93], 0x3b

        $sequence_3 = { 750b 8d4804 e8???????? c20800 51 8d4804 }
            // n = 6, score = 100
            //   750b                 | jne                 0xd
            //   8d4804               | lea                 ecx, [eax + 4]
            //   e8????????           |                     
            //   c20800               | ret                 8
            //   51                   | push                ecx
            //   8d4804               | lea                 ecx, [eax + 4]

        $sequence_4 = { 8b54241c 53 55 57 52 8b542430 52 }
            // n = 7, score = 100
            //   8b54241c             | mov                 edx, dword ptr [esp + 0x1c]
            //   53                   | push                ebx
            //   55                   | push                ebp
            //   57                   | push                edi
            //   52                   | push                edx
            //   8b542430             | mov                 edx, dword ptr [esp + 0x30]
            //   52                   | push                edx

        $sequence_5 = { c20400 8b542404 8b82f0010000 85c0 7416 8b4c2408 8b92d4010000 }
            // n = 7, score = 100
            //   c20400               | ret                 4
            //   8b542404             | mov                 edx, dword ptr [esp + 4]
            //   8b82f0010000         | mov                 eax, dword ptr [edx + 0x1f0]
            //   85c0                 | test                eax, eax
            //   7416                 | je                  0x18
            //   8b4c2408             | mov                 ecx, dword ptr [esp + 8]
            //   8b92d4010000         | mov                 edx, dword ptr [edx + 0x1d4]

        $sequence_6 = { 57 8bf1 8b4640 8d7810 57 68???????? }
            // n = 6, score = 100
            //   57                   | push                edi
            //   8bf1                 | mov                 esi, ecx
            //   8b4640               | mov                 eax, dword ptr [esi + 0x40]
            //   8d7810               | lea                 edi, [eax + 0x10]
            //   57                   | push                edi
            //   68????????           |                     

        $sequence_7 = { 8bce e8???????? 8b4f10 2b4f0c c1f902 85c9 }
            // n = 6, score = 100
            //   8bce                 | mov                 ecx, esi
            //   e8????????           |                     
            //   8b4f10               | mov                 ecx, dword ptr [edi + 0x10]
            //   2b4f0c               | sub                 ecx, dword ptr [edi + 0xc]
            //   c1f902               | sar                 ecx, 2
            //   85c9                 | test                ecx, ecx

        $sequence_8 = { 6689442458 8d7001 eb04 8b6c2424 8a44245a 240f 0c40 }
            // n = 7, score = 100
            //   6689442458           | mov                 word ptr [esp + 0x58], ax
            //   8d7001               | lea                 esi, [eax + 1]
            //   eb04                 | jmp                 6
            //   8b6c2424             | mov                 ebp, dword ptr [esp + 0x24]
            //   8a44245a             | mov                 al, byte ptr [esp + 0x5a]
            //   240f                 | and                 al, 0xf
            //   0c40                 | or                  al, 0x40

        $sequence_9 = { 8d442414 50 8b442420 8d4c2464 51 8d542420 52 }
            // n = 7, score = 100
            //   8d442414             | lea                 eax, [esp + 0x14]
            //   50                   | push                eax
            //   8b442420             | mov                 eax, dword ptr [esp + 0x20]
            //   8d4c2464             | lea                 ecx, [esp + 0x64]
            //   51                   | push                ecx
            //   8d542420             | lea                 edx, [esp + 0x20]
            //   52                   | push                edx

    condition:
        7 of them and filesize < 452608
}
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