SYMBOLCOMMON_NAMEaka. SYNONYMS
win.buer (Back to overview)

Buer

aka: Buerloader, RustyBuer
VTCollection    

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
2023-01-30 ⋅ Checkpoint ⋅ Arie Olshtein
Following the Scent of TrickGate: 6-Year-Old Packer Used to Deploy the Most Wanted Malware
Agent Tesla Azorult Buer Cerber Cobalt Strike Emotet Formbook HawkEye Keylogger Loki Password Stealer (PWS) Maze NetWire RC Remcos REvil TrickBot
2022-08-08 ⋅ Medium CSIS Techblog ⋅ Benoît Ancel
An inside view of domain anonymization as-a-service — the BraZZZerSFF infrastructure
Riltok magecart Anubis Azorult BetaBot Buer CoalaBot CryptBot DiamondFox DreamBot GCleaner ISFB Loki Password Stealer (PWS) MedusaLocker MeguminTrojan Nemty PsiX RedLine Stealer SmokeLoader STOP TinyNuke Vidar Zloader
2022-03-31 ⋅ Trellix ⋅ Jambul Tologonov, John Fokker
Conti Leaks: Examining the Panama Papers of Ransomware
LockBit Amadey Buer Conti IcedID LockBit Mailto Maze PhotoLoader Ryuk TrickBot
2022-03-17 ⋅ Trend Micro ⋅ Trend Micro Research
Navigating New Frontiers Trend Micro 2021 Annual Cybersecurity Report
REvil BazarBackdoor Buer IcedID QakBot REvil
2022-01-20 ⋅ TEHTRIS ⋅ TEHTRIS
Buer Loader Analysis, a Rusted malware program
Buer
2021-11-05 ⋅ Trend Micro ⋅ Christopher Boyton
A Review and Analysis of 2021 Buer Loader Campaigns
Buer
2021-11-05 ⋅ Trend Micro ⋅ Christopher Boyton
An Analysis of Buer Loader
Buer
2021-09-03 ⋅ Trend Micro ⋅ Mohamad Mokbel
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
2021-08-05 ⋅ Group-IB ⋅ Nikita Rostovcev, Viktor Okorokov
Prometheus TDS The key to success for Campo Loader, Hancitor, IcedID, and QBot
Prometheus Backdoor Buer campoloader Hancitor IcedID QakBot
2021-08-05 ⋅ The Record ⋅ Catalin Cimpanu
Meet Prometheus, the secret TDS behind some of today’s malware campaigns
Buer campoloader IcedID QakBot
2021-07-27 ⋅ Blackberry ⋅ BlackBerry Research & Intelligence Team
Old Dogs New Tricks: Attackers Adopt Exotic Programming Languages
elf.wellmess ElectroRAT BazarNimrod Buer Cobalt Strike Remcos Snake TeleBot WellMess Zebrocy
2021-07-19 ⋅ Fortinet ⋅ Fred Gutierrez, Val Saengphaibul
Signed, Sealed, and Delivered – Signed XLL File Delivers Buer Loader
Buer
2021-05-03 ⋅ Proofpoint ⋅ Bryan Campbell, Kelsey Merriman, Proofpoint Threat Research Team, Selena Larson
New Variant of Buer Loader Written in Rust
Buer
2021-05-03 ⋅ Medium walmartglobaltech ⋅ Jason Reaves, Joshua Platt
BuerLoader Updates
Buer
2021-03-18 ⋅ VIPRE ⋅ VIPRE Labs
Buer Loader Found in an Unusual Email Attachment
Buer
2021-03-01 ⋅ Group-IB ⋅ Oleg Skulkin, Roman Rezvukhin, Semyon Rogachev
Ransomware Uncovered 2020/2021
RansomEXX BazarBackdoor Buer Clop Conti DoppelPaymer Dridex Egregor IcedID Maze PwndLocker QakBot RansomEXX REvil Ryuk SDBbot TrickBot Zloader
2021-02-25 ⋅ ANSSI ⋅ CERT-FR
Ryuk Ransomware
BazarBackdoor Buer Conti Emotet Ryuk TrickBot
2021-02-02 ⋅ ⋅ CRONUP ⋅ Germán Fernández
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
2021-01-09 ⋅ Marco Ramilli's Blog ⋅ Marco Ramilli
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
2021-01-01 ⋅ Secureworks ⋅ SecureWorks
Threat Profile: GOLD SYMPHONY
Buer GOLD SYMPHONY
2021-01-01 ⋅ Secureworks ⋅ SecureWorks
Threat Profile: GOLD BLACKBURN
Buer Dyre TrickBot WIZARD SPIDER
2020-11-20 ⋅ ZDNet ⋅ Catalin Cimpanu
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
2020-11-18 ⋅ Minerva Labs ⋅ Eddy Bobritsky
Stopping BuerLoader With Minerva Lab's Hostile Environment Simulation module
Buer
2020-11-09 ⋅ Area 1 ⋅ Threat Research Team
Phishing Campaign Threatens Job Security, Drops Bazar and Buer Malware
BazarBackdoor Buer
2020-10-29 ⋅ Twitter (@SophosLabs) ⋅ SophosLabs
Tweet on similarities between BUER in-memory loader & RYUK in-memory loader
Buer Ryuk
2020-10-28 ⋅ SophosLabs Uncut ⋅ Anand Ajjan, Bill Kearny, Brett Cove, Elida Leite, Gabor Szappanos, Peter Mackenzie, Sean Gallagher, Syed Shahram
Hacks for sale: inside the Buer Loader malware-as-a-service
Buer Ryuk Zloader
2020-09-29 ⋅ Zscaler ⋅ Atinderpal Singh, Mohd Sadique
Spear Phishing Campaign Delivers Buer and Bazar Malware
BazarBackdoor Buer
2020-03-05 ⋅ Kaspersky Labs ⋅ AMR
Mokes and Buerak distributed under the guise of security certificates
Buer Mokes
2019-12-05 ⋅ KrabsOnSecurity ⋅ Mr. Krabs
Buer Loader, new Russian loader on the market with interesting persistence
Buer
2019-12-04 ⋅ Proofpoint ⋅ Axel F, Dennis Schwarz, Kafeine, Kelsey Merriman
Buer, a new loader emerges in the underground marketplace
Buer
2019-10-10 ⋅ Twitter (@StopMalvertisin) ⋅ Kimberly
Tweet on Malware Sample
Buer
Yara Rules
[TLP:WHITE] win_buer_auto (20230808 | Detects win.buer.)
rule win_buer_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-12-06"
        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 = "20231130"
        malpedia_hash = "fc8a0e9f343f6d6ded9e7df1a64dac0cc68d7351"
        malpedia_version = "20230808"
        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 = { 8b4014 8b00 8b4010 8945fc 61 8b45fc }
            // n = 6, score = 1100
            //   8b4014               | mov                 eax, dword ptr [eax + 0x14]
            //   8b00                 | mov                 eax, dword ptr [eax]
            //   8b4010               | mov                 eax, dword ptr [eax + 0x10]
            //   8945fc               | mov                 dword ptr [ebp - 4], eax
            //   61                   | popal               
            //   8b45fc               | mov                 eax, dword ptr [ebp - 4]

        $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 = { 60 64a130000000 8b400c 8b4014 8b00 8b4010 }
            // n = 6, score = 1100
            //   60                   | pushal              
            //   64a130000000         | mov                 eax, dword ptr fs:[0x30]
            //   8b400c               | mov                 eax, dword ptr [eax + 0xc]
            //   8b4014               | mov                 eax, dword ptr [eax + 0x14]
            //   8b00                 | mov                 eax, dword ptr [eax]
            //   8b4010               | mov                 eax, dword ptr [eax + 0x10]

        $sequence_3 = { 8bc2 eb19 33c0 85d2 7e13 3bc7 }
            // n = 6, score = 1100
            //   8bc2                 | mov                 eax, edx
            //   eb19                 | jmp                 0x1b
            //   33c0                 | xor                 eax, eax
            //   85d2                 | test                edx, edx
            //   7e13                 | jle                 0x15
            //   3bc7                 | cmp                 eax, edi

        $sequence_4 = { 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_5 = { c1e104 0bc8 6a02 5b }
            // n = 4, score = 1100
            //   c1e104               | shl                 ecx, 4
            //   0bc8                 | or                  ecx, eax
            //   6a02                 | push                2
            //   5b                   | pop                 ebx

        $sequence_6 = { 8945f8 ff15???????? 59 59 85c0 }
            // n = 5, score = 1100
            //   8945f8               | mov                 dword ptr [ebp - 8], eax
            //   ff15????????         |                     
            //   59                   | pop                 ecx
            //   59                   | pop                 ecx
            //   85c0                 | test                eax, eax

        $sequence_7 = { 8365fc00 53 56 57 60 64a130000000 8b400c }
            // n = 7, score = 1100
            //   8365fc00             | and                 dword ptr [ebp - 4], 0
            //   53                   | push                ebx
            //   56                   | push                esi
            //   57                   | push                edi
            //   60                   | pushal              
            //   64a130000000         | mov                 eax, dword ptr fs:[0x30]
            //   8b400c               | mov                 eax, dword ptr [eax + 0xc]

        $sequence_8 = { c744240402000000 8d442428 c7442408???????? c744240c01000000 }
            // n = 4, score = 300
            //   c744240402000000     | mov                 dword ptr [esp + 4], 2
            //   8d442428             | lea                 eax, [esp + 0x28]
            //   c7442408????????     |                     
            //   c744240c01000000     | mov                 dword ptr [esp + 0xc], 1

        $sequence_9 = { e8???????? 80fb03 7705 80fb02 }
            // n = 4, score = 300
            //   e8????????           |                     
            //   80fb03               | cmp                 bl, 3
            //   7705                 | ja                  7
            //   80fb02               | cmp                 bl, 2

        $sequence_10 = { e8???????? 0f0b b92c000000 ba01000000 e8???????? 0f0b 89f9 }
            // n = 7, score = 300
            //   e8????????           |                     
            //   0f0b                 | ud2                 
            //   b92c000000           | mov                 ecx, 0x2c
            //   ba01000000           | mov                 edx, 1
            //   e8????????           |                     
            //   0f0b                 | ud2                 
            //   89f9                 | mov                 ecx, edi

        $sequence_11 = { c744240401000000 c7442408???????? c744240c01000000 89442410 }
            // n = 4, score = 300
            //   c744240401000000     | mov                 dword ptr [esp + 4], 1
            //   c7442408????????     |                     
            //   c744240c01000000     | mov                 dword ptr [esp + 0xc], 1
            //   89442410             | mov                 dword ptr [esp + 0x10], eax

        $sequence_12 = { e8???????? 56 6a00 50 e8???????? c7471c01000000 }
            // n = 6, score = 300
            //   e8????????           |                     
            //   56                   | push                esi
            //   6a00                 | push                0
            //   50                   | push                eax
            //   e8????????           |                     
            //   c7471c01000000       | mov                 dword ptr [edi + 0x1c], 1

        $sequence_13 = { c744240800000000 57 e8???????? 85c0 }
            // n = 4, score = 300
            //   c744240800000000     | mov                 dword ptr [esp + 8], 0
            //   57                   | push                edi
            //   e8????????           |                     
            //   85c0                 | test                eax, eax

        $sequence_14 = { cd29 0f0b cc 8b442404 833800 7406 ba???????? }
            // n = 7, score = 300
            //   cd29                 | int                 0x29
            //   0f0b                 | ud2                 
            //   cc                   | int3                
            //   8b442404             | mov                 eax, dword ptr [esp + 4]
            //   833800               | cmp                 dword ptr [eax], 0
            //   7406                 | je                  8
            //   ba????????           |                     

        $sequence_15 = { e8???????? 80fb05 ba01000000 0fb6c3 }
            // n = 4, score = 300
            //   e8????????           |                     
            //   80fb05               | cmp                 bl, 5
            //   ba01000000           | mov                 edx, 1
            //   0fb6c3               | movzx               eax, bl

    condition:
        7 of them and filesize < 3031040
}
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