SYMBOLCOMMON_NAMEaka. SYNONYMS
win.ragnarok (Back to overview)

Ragnarok

VTCollection    

According to Bleeping Computer, the ransomware is used in targeted attacks against unpatched Citrix servers. It excludes Russian and Chinese targets using the system's Language ID for filtering. It also tries to disable Windows Defender and has a number of UNIX filepath references in its strings. Encryption method is AES using a dynamically generated key, then bundling this key up via RSA.

References
2022-06-23 ⋅ Kaspersky ⋅ Danila Nasonov, Natalya Shornikova, Nikita Nazarov, Vasily Davydov, Vladislav Burtsev
The hateful eight: Kaspersky’s guide to modern ransomware groups’ TTPs
Conti Hive BlackByte BlackCat Clop LockBit Mespinoza Ragnarok
2022-03-17 ⋅ Sophos ⋅ Tilly Travers
The Ransomware Threat Intelligence Center
ATOMSILO Avaddon AvosLocker BlackKingdom Ransomware BlackMatter Conti Cring DarkSide dearcry Dharma Egregor Entropy Epsilon Red Gandcrab Karma LockBit LockFile Mailto Maze Nefilim RagnarLocker Ragnarok REvil RobinHood Ryuk SamSam Snatch WannaCryptor WastedLocker
2021-08-26 ⋅ Bleeping Computer ⋅ Ionut Ilascu
Ragnarok ransomware releases master decryptor after shutdown
Ragnarok
2021-05-10 ⋅ DarkTracer ⋅ DarkTracer
Intelligence Report on Ransomware Gangs on the DarkWeb: List of victim organizations attacked by ransomware gangs released on the DarkWeb
RansomEXX Avaddon Babuk Clop Conti Cuba DarkSide DoppelPaymer Egregor Hades LockBit Mailto Maze MedusaLocker Mespinoza Mount Locker Nefilim Nemty Pay2Key PwndLocker RagnarLocker Ragnarok RansomEXX REvil Sekhmet SunCrypt ThunderX
2021-02-23 ⋅ CrowdStrike ⋅ CrowdStrike
2021 Global Threat Report
RansomEXX Amadey Anchor Avaddon BazarBackdoor Clop Cobalt Strike Conti Cutwail DanaBot DarkSide DoppelPaymer Dridex Egregor Emotet Hakbit IcedID JSOutProx KerrDown LockBit Mailto Maze MedusaLocker Mespinoza Mount Locker NedDnLoader Nemty Pay2Key PlugX Pushdo PwndLocker PyXie QakBot Quasar RAT RagnarLocker Ragnarok RansomEXX REvil Ryuk Sekhmet ShadowPad SmokeLoader Snake SUNBURST SunCrypt TEARDROP TrickBot WastedLocker Winnti Zloader Evilnum OUTLAW SPIDER RIDDLE SPIDER SOLAR SPIDER VIKING SPIDER
2020-05-21 ⋅ ⋅ Sophos ⋅ SophosLabs Uncut
Asnarök attackers twice modified attack midstream
NOTROBIN Ragnarok
2020-05-04 ⋅ blackarrow ⋅ Borja Merino
Ragnarok Stopper: development of a vaccine
Ragnarok
2020-01-28 ⋅ Bleeping Computer ⋅ Lawrence Abrams
Ragnarok Ransomware Targets Citrix ADC, Disables Windows Defender
Ragnarok
2020-01-25 ⋅ Github (k-vitali) ⋅ Vitali Kremez
Extracted Config for Ragnarok Ransomware
Ragnarok
Yara Rules
[TLP:WHITE] win_ragnarok_auto (20241030 | Detects win.ragnarok.)
rule win_ragnarok_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2024-10-31"
        version = "1"
        description = "Detects win.ragnarok."
        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.ragnarok"
        malpedia_rule_date = "20241030"
        malpedia_hash = "26e26953c49c8efafbf72a38076855d578e0a2e4"
        malpedia_version = "20241030"
        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 = { 51 ff35???????? ffd3 8bf8 8d8540ffffff 50 }
            // n = 6, score = 200
            //   51                   | push                ecx
            //   ff35????????         |                     
            //   ffd3                 | call                ebx
            //   8bf8                 | mov                 edi, eax
            //   8d8540ffffff         | lea                 eax, [ebp - 0xc0]
            //   50                   | push                eax

        $sequence_1 = { 0fb6c9 0fb689104b4300 c1e108 33d9 8b4d10 c1e910 0fb6c9 }
            // n = 7, score = 200
            //   0fb6c9               | movzx               ecx, cl
            //   0fb689104b4300       | movzx               ecx, byte ptr [ecx + 0x434b10]
            //   c1e108               | shl                 ecx, 8
            //   33d9                 | xor                 ebx, ecx
            //   8b4d10               | mov                 ecx, dword ptr [ebp + 0x10]
            //   c1e910               | shr                 ecx, 0x10
            //   0fb6c9               | movzx               ecx, cl

        $sequence_2 = { 238574fdffff 338568fdffff 03d9 8b8d58fdffff 13f8 8b8538fdffff 031cc588af4200 }
            // n = 7, score = 200
            //   238574fdffff         | and                 eax, dword ptr [ebp - 0x28c]
            //   338568fdffff         | xor                 eax, dword ptr [ebp - 0x298]
            //   03d9                 | add                 ebx, ecx
            //   8b8d58fdffff         | mov                 ecx, dword ptr [ebp - 0x2a8]
            //   13f8                 | adc                 edi, eax
            //   8b8538fdffff         | mov                 eax, dword ptr [ebp - 0x2c8]
            //   031cc588af4200       | add                 ebx, dword ptr [eax*8 + 0x42af88]

        $sequence_3 = { 83c410 5d c3 e8???????? 50 e8???????? 59 }
            // n = 7, score = 200
            //   83c410               | add                 esp, 0x10
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   e8????????           |                     
            //   50                   | push                eax
            //   e8????????           |                     
            //   59                   | pop                 ecx

        $sequence_4 = { 88043e 46 83fe40 7ce6 }
            // n = 4, score = 200
            //   88043e               | mov                 byte ptr [esi + edi], al
            //   46                   | inc                 esi
            //   83fe40               | cmp                 esi, 0x40
            //   7ce6                 | jl                  0xffffffe8

        $sequence_5 = { 0b45a0 33c1 895db0 0345e8 03c2 }
            // n = 5, score = 200
            //   0b45a0               | or                  eax, dword ptr [ebp - 0x60]
            //   33c1                 | xor                 eax, ecx
            //   895db0               | mov                 dword ptr [ebp - 0x50], ebx
            //   0345e8               | add                 eax, dword ptr [ebp - 0x18]
            //   03c2                 | add                 eax, edx

        $sequence_6 = { 8bf8 83c40c 85ff 7576 8b4d08 8bc6 99 }
            // n = 7, score = 200
            //   8bf8                 | mov                 edi, eax
            //   83c40c               | add                 esp, 0xc
            //   85ff                 | test                edi, edi
            //   7576                 | jne                 0x78
            //   8b4d08               | mov                 ecx, dword ptr [ebp + 8]
            //   8bc6                 | mov                 eax, esi
            //   99                   | cdq                 

        $sequence_7 = { 8b048528754300 5f 894df4 c644032b0a 8b5d08 753b }
            // n = 6, score = 200
            //   8b048528754300       | mov                 eax, dword ptr [eax*4 + 0x437528]
            //   5f                   | pop                 edi
            //   894df4               | mov                 dword ptr [ebp - 0xc], ecx
            //   c644032b0a           | mov                 byte ptr [ebx + eax + 0x2b], 0xa
            //   8b5d08               | mov                 ebx, dword ptr [ebp + 8]
            //   753b                 | jne                 0x3d

        $sequence_8 = { 334d0c 034df8 034d98 c1c00a 8945ac 8b450c c1c105 }
            // n = 7, score = 200
            //   334d0c               | xor                 ecx, dword ptr [ebp + 0xc]
            //   034df8               | add                 ecx, dword ptr [ebp - 8]
            //   034d98               | add                 ecx, dword ptr [ebp - 0x68]
            //   c1c00a               | rol                 eax, 0xa
            //   8945ac               | mov                 dword ptr [ebp - 0x54], eax
            //   8b450c               | mov                 eax, dword ptr [ebp + 0xc]
            //   c1c105               | rol                 ecx, 5

        $sequence_9 = { 0f87a9000000 ff24858d6e4100 ff7510 ff750c }
            // n = 4, score = 200
            //   0f87a9000000         | ja                  0xaf
            //   ff24858d6e4100       | jmp                 dword ptr [eax*4 + 0x416e8d]
            //   ff7510               | push                dword ptr [ebp + 0x10]
            //   ff750c               | push                dword ptr [ebp + 0xc]

    condition:
        7 of them and filesize < 483328
}
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