SYMBOLCOMMON_NAMEaka. SYNONYMS
win.buer (Back to overview)

Buer

aka: Buerloader, RustyBuer

Buer is a downloader sold on underground forums and used by threat actors to deliver payload malware onto target machines. It has been observed in email campaigns and has been sold as a service since August 2019.

References
2021-11-05Trend MicroChristopher Boyton
@online{boyton:20211105:review:a1394e6, author = {Christopher Boyton}, title = {{A Review and Analysis of 2021 Buer Loader Campaigns}}, date = {2021-11-05}, organization = {Trend Micro}, url = {https://www.trendmicro.com/en_us/research/21/k/a-review-and-analysis-of-2021-buer-loader-campaigns.html}, language = {English}, urldate = {2021-11-08} } A Review and Analysis of 2021 Buer Loader Campaigns
Buer
2021-11-05Trend MicroChristopher Boyton
@techreport{boyton:20211105:analysis:2711253, author = {Christopher Boyton}, title = {{An Analysis of Buer Loader}}, date = {2021-11-05}, institution = {Trend Micro}, url = {https://www.trendmicro.com/content/dam/trendmicro/global/en/research/21/k/a-review-and-analysis-of-2021-buer-loader-campaigns/TechnicalBrief-An-Analysis-of-Buer-Loader.pdf}, language = {English}, urldate = {2021-11-08} } An Analysis of Buer Loader
Buer
2021-09-03Trend MicroMohamad Mokbel
@techreport{mokbel:20210903:state:df86499, author = {Mohamad Mokbel}, title = {{The State of SSL/TLS Certificate Usage in Malware C&C Communications}}, date = {2021-09-03}, institution = {Trend Micro}, url = {https://www.trendmicro.com/content/dam/trendmicro/global/en/research/21/i/ssl-tls-technical-brief/ssl-tls-technical-brief.pdf}, language = {English}, urldate = {2021-09-19} } The State of SSL/TLS Certificate Usage in Malware C&C Communications
AdWind ostap AsyncRAT BazarBackdoor BitRAT Buer Chthonic CloudEyE Cobalt Strike DCRat Dridex FindPOS GootKit Gozi IcedID ISFB Nanocore RAT Orcus RAT PandaBanker Qadars QakBot Quasar RAT Rockloader ServHelper Shifu SManager TorrentLocker TrickBot Vawtrak Zeus Zloader
2021-08-05Group-IBViktor Okorokov, Nikita Rostovcev
@online{okorokov:20210805:prometheus:38ab6a6, author = {Viktor Okorokov and Nikita Rostovcev}, title = {{Prometheus TDS The key to success for Campo Loader, Hancitor, IcedID, and QBot}}, date = {2021-08-05}, organization = {Group-IB}, url = {https://blog.group-ib.com/prometheus-tds}, language = {English}, urldate = {2021-08-06} } Prometheus TDS The key to success for Campo Loader, Hancitor, IcedID, and QBot
Buer campoloader Hancitor IcedID QakBot
2021-08-05The RecordCatalin Cimpanu
@online{cimpanu:20210805:meet:bce8310, author = {Catalin Cimpanu}, title = {{Meet Prometheus, the secret TDS behind some of today’s malware campaigns}}, date = {2021-08-05}, organization = {The Record}, url = {https://therecord.media/meet-prometheus-the-secret-tds-behind-some-of-todays-malware-campaigns/}, language = {English}, urldate = {2021-08-06} } Meet Prometheus, the secret TDS behind some of today’s malware campaigns
Buer campoloader IcedID QakBot
2021-07-27BlackberryBlackBerry Research & Intelligence Team
@techreport{team:20210727:old:3060d53, author = {BlackBerry Research & Intelligence Team}, title = {{Old Dogs New Tricks: Attackers Adopt Exotic Programming Languages}}, date = {2021-07-27}, institution = {Blackberry}, url = {https://www.blackberry.com/content/dam/blackberry-com/asset/enterprise/pdf/direct/report-old-dogs-new-tricks.pdf}, language = {English}, urldate = {2021-07-27} } Old Dogs New Tricks: Attackers Adopt Exotic Programming Languages
elf.wellmess ElectroRAT BazarNimrod Buer Cobalt Strike Remcos Snake TeleBot WellMess Zebrocy
2021-07-19FortinetVal Saengphaibul, Fred Gutierrez
@online{saengphaibul:20210719:signed:d9f809c, author = {Val Saengphaibul and Fred Gutierrez}, title = {{Signed, Sealed, and Delivered – Signed XLL File Delivers Buer Loader}}, date = {2021-07-19}, organization = {Fortinet}, url = {https://www.fortinet.com/blog/threat-research/signed-sealed-and-delivered-signed-xll-file-delivers-buer-loader}, language = {English}, urldate = {2021-07-26} } Signed, Sealed, and Delivered – Signed XLL File Delivers Buer Loader
Buer
2021-05-03ProofpointKelsey Merriman, Bryan Campbell, Selena Larson, Proofpoint Threat Research Team
@online{merriman:20210503:new:cd4d275, author = {Kelsey Merriman and Bryan Campbell and Selena Larson and Proofpoint Threat Research Team}, title = {{New Variant of Buer Loader Written in Rust}}, date = {2021-05-03}, organization = {Proofpoint}, url = {https://www.proofpoint.com/us/blog/threat-insight/new-variant-buer-loader-written-rust}, language = {English}, urldate = {2021-05-03} } New Variant of Buer Loader Written in Rust
Buer
2021-05-03Medium walmartglobaltechJoshua Platt, Jason Reaves
@online{platt:20210503:buerloader:2aa3e3f, author = {Joshua Platt and Jason Reaves}, title = {{BuerLoader Updates}}, date = {2021-05-03}, organization = {Medium walmartglobaltech}, url = {https://medium.com/walmartglobaltech/buerloader-updates-3e34c1949b96}, language = {English}, urldate = {2021-05-04} } BuerLoader Updates
Buer
2021-03Group-IBOleg Skulkin, Roman Rezvukhin, Semyon Rogachev
@techreport{skulkin:202103:ransomware:992ca10, author = {Oleg Skulkin and Roman Rezvukhin and Semyon Rogachev}, title = {{Ransomware Uncovered 2020/2021}}, date = {2021-03}, institution = {Group-IB}, url = {https://web.archive.org/web/20210305181115/https://cisoclub.ru/doc/otchet-kompanii-group-ib-ransomware-uncovered-2020-2021/?bp-attachment=group-ib_ransomware_uncovered_2020-2021.pdf}, language = {English}, urldate = {2021-06-16} } Ransomware Uncovered 2020/2021
RansomEXX BazarBackdoor Buer Clop Conti DoppelPaymer Dridex Egregor IcedID Maze PwndLocker QakBot RansomEXX REvil Ryuk SDBbot TrickBot Zloader
2021-02-25ANSSICERT-FR
@techreport{certfr:20210225:ryuk:7895e12, author = {CERT-FR}, title = {{Ryuk Ransomware}}, date = {2021-02-25}, institution = {ANSSI}, url = {https://www.cert.ssi.gouv.fr/uploads/CERTFR-2021-CTI-006.pdf}, language = {English}, urldate = {2021-03-02} } Ryuk Ransomware
BazarBackdoor Buer Conti Emotet Ryuk TrickBot
2021-02-02CRONUPGermán Fernández
@online{fernndez:20210202:de:6ff4f3a, author = {Germán Fernández}, title = {{De ataque con Malware a incidente de Ransomware}}, date = {2021-02-02}, organization = {CRONUP}, url = {https://www.cronup.com/post/de-ataque-con-malware-a-incidente-de-ransomware}, language = {Spanish}, urldate = {2021-03-02} } De ataque con Malware a incidente de Ransomware
Avaddon BazarBackdoor Buer Clop Cobalt Strike Conti DanaBot Dharma Dridex Egregor Emotet Empire Downloader FriedEx GootKit IcedID MegaCortex Nemty Phorpiex PwndLocker PyXie QakBot RansomEXX REvil Ryuk SDBbot SmokeLoader TrickBot Zloader
2021-01-09Marco Ramilli's BlogMarco Ramilli
@online{ramilli:20210109:command:d720b27, author = {Marco Ramilli}, title = {{Command and Control Traffic Patterns}}, date = {2021-01-09}, organization = {Marco Ramilli's Blog}, url = {https://marcoramilli.com/2021/01/09/c2-traffic-patterns-personal-notes/}, language = {English}, urldate = {2021-05-17} } Command and Control Traffic Patterns
ostap LaZagne Agent Tesla Azorult Buer Cobalt Strike DanaBot DarkComet Dridex Emotet Formbook IcedID ISFB NetWire RC PlugX Quasar RAT SmokeLoader TrickBot
2021SecureworksSecureWorks
@online{secureworks:2021:threat:07bd94a, author = {SecureWorks}, title = {{Threat Profile: GOLD SYMPHONY}}, date = {2021}, organization = {Secureworks}, url = {http://www.secureworks.com/research/threat-profiles/gold-symphony}, language = {English}, urldate = {2021-05-28} } Threat Profile: GOLD SYMPHONY
Buer GOLD SYMPHONY
2021SecureworksSecureWorks
@online{secureworks:2021:threat:4e7c443, author = {SecureWorks}, title = {{Threat Profile: GOLD BLACKBURN}}, date = {2021}, organization = {Secureworks}, url = {http://www.secureworks.com/research/threat-profiles/gold-blackburn}, language = {English}, urldate = {2021-05-28} } Threat Profile: GOLD BLACKBURN
Buer Dyre TrickBot WIZARD SPIDER
2020-11-20ZDNetCatalin Cimpanu
@online{cimpanu:20201120:malware:0b8ff59, author = {Catalin Cimpanu}, title = {{The malware that usually installs ransomware and you need to remove right away}}, date = {2020-11-20}, organization = {ZDNet}, url = {https://www.zdnet.com/article/the-malware-that-usually-installs-ransomware-and-you-need-to-remove-right-away/}, language = {English}, urldate = {2020-11-23} } The malware that usually installs ransomware and you need to remove right away
Avaddon BazarBackdoor Buer Clop Cobalt Strike Conti DoppelPaymer Dridex Egregor Emotet FriedEx MegaCortex Phorpiex PwndLocker QakBot Ryuk SDBbot TrickBot Zloader
2020-11-18Minerva LabsEddy Bobritsky
@online{bobritsky:20201118:stopping:e5c486b, author = {Eddy Bobritsky}, title = {{Stopping BuerLoader With Minerva Lab's Hostile Environment Simulation module}}, date = {2020-11-18}, organization = {Minerva Labs}, url = {https://blog.minerva-labs.com/stopping-buerloader}, language = {English}, urldate = {2020-11-19} } Stopping BuerLoader With Minerva Lab's Hostile Environment Simulation module
Buer
2020-11-09Area 1Threat Research Team
@online{team:20201109:phishing:a25a567, author = {Threat Research Team}, title = {{Phishing Campaign Threatens Job Security, Drops Bazar and Buer Malware}}, date = {2020-11-09}, organization = {Area 1}, url = {https://www.area1security.com/blog/trickbot-spear-phishing-drops-bazar-buer-malware/}, language = {English}, urldate = {2020-11-18} } Phishing Campaign Threatens Job Security, Drops Bazar and Buer Malware
BazarBackdoor Buer
2020-10-29Twitter (@SophosLabs)SophosLabs
@online{sophoslabs:20201029:similarities:408a640, author = {SophosLabs}, title = {{Tweet on similarities between BUER in-memory loader & RYUK in-memory loader}}, date = {2020-10-29}, organization = {Twitter (@SophosLabs)}, url = {https://twitter.com/SophosLabs/status/1321844306970251265}, language = {English}, urldate = {2020-11-02} } Tweet on similarities between BUER in-memory loader & RYUK in-memory loader
Buer Ryuk
2020-10-28SophosLabs UncutSean Gallagher, Peter Mackenzie, Elida Leite, Syed Shahram, Bill Kearny, Anand Ajjan, Brett Cove, Gabor Szappanos
@online{gallagher:20201028:hacks:8e1d051, author = {Sean Gallagher and Peter Mackenzie and Elida Leite and Syed Shahram and Bill Kearny and Anand Ajjan and Brett Cove and Gabor Szappanos}, title = {{Hacks for sale: inside the Buer Loader malware-as-a-service}}, date = {2020-10-28}, organization = {SophosLabs Uncut}, url = {https://news.sophos.com/en-us/2020/10/28/hacks-for-sale-inside-the-buer-loader-malware-as-a-service/}, language = {English}, urldate = {2020-11-02} } Hacks for sale: inside the Buer Loader malware-as-a-service
Buer Ryuk Zloader
2020-09-29ZscalerMohd Sadique, Atinderpal Singh
@online{sadique:20200929:spear:de79be6, author = {Mohd Sadique and Atinderpal Singh}, title = {{Spear Phishing Campaign Delivers Buer and Bazar Malware}}, date = {2020-09-29}, organization = {Zscaler}, url = {https://www.zscaler.com/blogs/research/spear-phishing-campaign-delivers-buer-and-bazar-malware}, language = {English}, urldate = {2020-10-15} } Spear Phishing Campaign Delivers Buer and Bazar Malware
BazarBackdoor Buer
2020-03-05Kaspersky LabsAMR
@online{amr:20200305:mokes:698295f, author = {AMR}, title = {{Mokes and Buerak distributed under the guise of security certificates}}, date = {2020-03-05}, organization = {Kaspersky Labs}, url = {https://securelist.com/mokes-and-buerak-distributed-under-the-guise-of-security-certificates/96324/}, language = {English}, urldate = {2020-03-09} } Mokes and Buerak distributed under the guise of security certificates
Buer Mokes
2019-12-05KrabsOnSecurityMr. Krabs
@online{krabs:20191205:buer:9c3cf72, author = {Mr. Krabs}, title = {{Buer Loader, new Russian loader on the market with interesting persistence}}, date = {2019-12-05}, organization = {KrabsOnSecurity}, url = {https://krabsonsecurity.com/2019/12/05/buer-loader-new-russian-loader-on-the-market-with-interesting-persistence/}, language = {English}, urldate = {2020-01-08} } Buer Loader, new Russian loader on the market with interesting persistence
Buer
2019-12-04ProofpointKelsey Merriman, Dennis Schwarz, Kafeine, Axel F
@online{merriman:20191204:buer:6c413aa, author = {Kelsey Merriman and Dennis Schwarz and Kafeine and Axel F}, title = {{Buer, a new loader emerges in the underground marketplace}}, date = {2019-12-04}, organization = {Proofpoint}, url = {https://www.proofpoint.com/us/threat-insight/post/buer-new-loader-emerges-underground-marketplace}, language = {English}, urldate = {2020-01-06} } Buer, a new loader emerges in the underground marketplace
Buer
2019-10-10Twitter (@StopMalvertisin)Kimberly
@online{kimberly:20191010:malware:032ed3c, author = {Kimberly}, title = {{Tweet on Malware Sample}}, date = {2019-10-10}, organization = {Twitter (@StopMalvertisin)}, url = {https://twitter.com/StopMalvertisin/status/1182505434231398401}, language = {English}, urldate = {2020-01-10} } Tweet on Malware Sample
Buer
Yara Rules
[TLP:WHITE] win_buer_auto (20211008 | Detects win.buer.)
rule win_buer_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2021-10-07"
        version = "1"
        description = "Detects win.buer."
        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.buer"
        malpedia_rule_date = "20211007"
        malpedia_hash = "e5b790e0f888f252d49063a1251ca60ec2832535"
        malpedia_version = "20211008"
        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 = { 8b4b44 8b5348 8b734c 8b7b50 8b4340 0345f8 }
            // n = 6, score = 1100
            //   8b4b44               | mov                 ecx, dword ptr [ebx + 0x44]
            //   8b5348               | mov                 edx, dword ptr [ebx + 0x48]
            //   8b734c               | mov                 esi, dword ptr [ebx + 0x4c]
            //   8b7b50               | mov                 edi, dword ptr [ebx + 0x50]
            //   8b4340               | mov                 eax, dword ptr [ebx + 0x40]
            //   0345f8               | add                 eax, dword ptr [ebp - 8]

        $sequence_1 = { 7507 e8???????? eb05 e8???????? 46 83fe20 7cd1 }
            // n = 7, score = 1100
            //   7507                 | jne                 9
            //   e8????????           |                     
            //   eb05                 | jmp                 7
            //   e8????????           |                     
            //   46                   | inc                 esi
            //   83fe20               | cmp                 esi, 0x20
            //   7cd1                 | jl                  0xffffffd3

        $sequence_2 = { 0fb706 83c602 6a08 50 }
            // n = 4, score = 1100
            //   0fb706               | movzx               eax, word ptr [esi]
            //   83c602               | add                 esi, 2
            //   6a08                 | push                8
            //   50                   | push                eax

        $sequence_3 = { 8b55e8 015158 8b55d8 894148 8b45dc 03c6 89414c }
            // n = 7, score = 1100
            //   8b55e8               | mov                 edx, dword ptr [ebp - 0x18]
            //   015158               | add                 dword ptr [ecx + 0x58], edx
            //   8b55d8               | mov                 edx, dword ptr [ebp - 0x28]
            //   894148               | mov                 dword ptr [ecx + 0x48], eax
            //   8b45dc               | mov                 eax, dword ptr [ebp - 0x24]
            //   03c6                 | add                 eax, esi
            //   89414c               | mov                 dword ptr [ecx + 0x4c], eax

        $sequence_4 = { e8???????? 8d5001 85ff 7504 8bc2 eb19 33c0 }
            // n = 7, score = 1100
            //   e8????????           |                     
            //   8d5001               | lea                 edx, dword ptr [eax + 1]
            //   85ff                 | test                edi, edi
            //   7504                 | jne                 6
            //   8bc2                 | mov                 eax, edx
            //   eb19                 | jmp                 0x1b
            //   33c0                 | xor                 eax, eax

        $sequence_5 = { 89414c 8b45fc 03c7 894150 8b45ec }
            // n = 5, score = 1100
            //   89414c               | mov                 dword ptr [ecx + 0x4c], eax
            //   8b45fc               | mov                 eax, dword ptr [ebp - 4]
            //   03c7                 | add                 eax, edi
            //   894150               | mov                 dword ptr [ecx + 0x50], eax
            //   8b45ec               | mov                 eax, dword ptr [ebp - 0x14]

        $sequence_6 = { 894154 5b c9 c3 }
            // n = 4, score = 1100
            //   894154               | mov                 dword ptr [ecx + 0x54], eax
            //   5b                   | pop                 ebx
            //   c9                   | leave               
            //   c3                   | ret                 

        $sequence_7 = { 8a0c46 880c18 40 3bc2 7cf1 eb02 }
            // n = 6, score = 1100
            //   8a0c46               | mov                 cl, byte ptr [esi + eax*2]
            //   880c18               | mov                 byte ptr [eax + ebx], cl
            //   40                   | inc                 eax
            //   3bc2                 | cmp                 eax, edx
            //   7cf1                 | jl                  0xfffffff3
            //   eb02                 | jmp                 4

        $sequence_8 = { ba01000000 57 56 6a02 }
            // n = 4, score = 200
            //   ba01000000           | mov                 edx, 1
            //   57                   | push                edi
            //   56                   | push                esi
            //   6a02                 | push                2

        $sequence_9 = { ba01000000 6683fd0a 72d2 6683fd64 }
            // n = 4, score = 200
            //   ba01000000           | mov                 edx, 1
            //   6683fd0a             | cmp                 bp, 0xa
            //   72d2                 | jb                  0xffffffd4
            //   6683fd64             | cmp                 bp, 0x64

        $sequence_10 = { ba01000000 50 57 6a02 68???????? eb39 }
            // n = 6, score = 200
            //   ba01000000           | mov                 edx, 1
            //   50                   | push                eax
            //   57                   | push                edi
            //   6a02                 | push                2
            //   68????????           |                     
            //   eb39                 | jmp                 0x3b

        $sequence_11 = { ba01000000 29fe 56 50 }
            // n = 4, score = 200
            //   ba01000000           | mov                 edx, 1
            //   29fe                 | sub                 esi, edi
            //   56                   | push                esi
            //   50                   | push                eax

        $sequence_12 = { ba01000000 29ce 89e9 56 50 6a02 68???????? }
            // n = 7, score = 200
            //   ba01000000           | mov                 edx, 1
            //   29ce                 | sub                 esi, ecx
            //   89e9                 | mov                 ecx, ebp
            //   56                   | push                esi
            //   50                   | push                eax
            //   6a02                 | push                2
            //   68????????           |                     

        $sequence_13 = { ba01000000 662e0f1f840000000000 8bb484f4010000 f7d6 }
            // n = 4, score = 200
            //   ba01000000           | mov                 edx, 1
            //   662e0f1f840000000000     | nop    word ptr cs:[eax + eax]
            //   8bb484f4010000       | mov                 esi, dword ptr [esp + eax*4 + 0x1f4]
            //   f7d6                 | not                 esi

        $sequence_14 = { ba01000000 3c0f 7547 85d2 }
            // n = 4, score = 200
            //   ba01000000           | mov                 edx, 1
            //   3c0f                 | cmp                 al, 0xf
            //   7547                 | jne                 0x49
            //   85d2                 | test                edx, edx

        $sequence_15 = { c1e206 09fa eb40 31ed 89c1 c1e706 }
            // n = 6, score = 200
            //   c1e206               | shl                 edx, 6
            //   09fa                 | or                  edx, edi
            //   eb40                 | jmp                 0x42
            //   31ed                 | xor                 ebp, ebp
            //   89c1                 | mov                 ecx, eax
            //   c1e706               | shl                 edi, 6

    condition:
        7 of them and filesize < 2518016
}
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