SYMBOLCOMMON_NAMEaka. SYNONYMS
win.cryptoshield (Back to overview)

CryptoShield


There is no description at this point.

References
2017-03-15Bleeping ComputerLawrence Abrams
@online{abrams:20170315:revenge:b047d2f, author = {Lawrence Abrams}, title = {{Revenge Ransomware, a CryptoMix Variant, Being Distributed by RIG Exploit Kit}}, date = {2017-03-15}, organization = {Bleeping Computer}, url = {https://www.bleepingcomputer.com/news/security/revenge-ransomware-a-cryptomix-variant-being-distributed-by-rig-exploit-kit/}, language = {English}, urldate = {2019-12-20} } Revenge Ransomware, a CryptoMix Variant, Being Distributed by RIG Exploit Kit
CryptoShield
2017-03-14Broad AnalysisBroad Analysis
@online{analysis:20170314:rig:56f3334, author = {Broad Analysis}, title = {{Rig Exploit Kit via the EiTest delivers CryptoShield/REVENGE ransomware}}, date = {2017-03-14}, organization = {Broad Analysis}, url = {http://www.broadanalysis.com/2017/03/14/rig-exploit-kit-via-the-eitest-delivers-cryptoshieldrevenge-ransomware/}, language = {English}, urldate = {2020-01-07} } Rig Exploit Kit via the EiTest delivers CryptoShield/REVENGE ransomware
CryptoShield
Yara Rules
[TLP:WHITE] win_cryptoshield_auto (20230407 | Detects win.cryptoshield.)
rule win_cryptoshield_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-03-28"
        version = "1"
        description = "Detects win.cryptoshield."
        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.cryptoshield"
        malpedia_rule_date = "20230328"
        malpedia_hash = "9d2d75cef573c1c2d861f5197df8f563b05a305d"
        malpedia_version = "20230407"
        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 = { 6a00 56 ff15???????? 6a00 8d85e8fbffff 50 6a01 }
            // n = 7, score = 300
            //   6a00                 | push                0
            //   56                   | push                esi
            //   ff15????????         |                     
            //   6a00                 | push                0
            //   8d85e8fbffff         | lea                 eax, [ebp - 0x418]
            //   50                   | push                eax
            //   6a01                 | push                1

        $sequence_1 = { 57 6a01 57 ff75fc ff15???????? 85c0 7461 }
            // n = 7, score = 300
            //   57                   | push                edi
            //   6a01                 | push                1
            //   57                   | push                edi
            //   ff75fc               | push                dword ptr [ebp - 4]
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   7461                 | je                  0x63

        $sequence_2 = { ff15???????? 85c0 7508 ffd3 8bf8 }
            // n = 5, score = 300
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   7508                 | jne                 0xa
            //   ffd3                 | call                ebx
            //   8bf8                 | mov                 edi, eax

        $sequence_3 = { 5f 5e 8913 5b 5d c3 }
            // n = 6, score = 300
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi
            //   8913                 | mov                 dword ptr [ebx], edx
            //   5b                   | pop                 ebx
            //   5d                   | pop                 ebp
            //   c3                   | ret                 

        $sequence_4 = { 0f8522010000 68???????? 68???????? ffd6 85c0 0f850e010000 }
            // n = 6, score = 300
            //   0f8522010000         | jne                 0x128
            //   68????????           |                     
            //   68????????           |                     
            //   ffd6                 | call                esi
            //   85c0                 | test                eax, eax
            //   0f850e010000         | jne                 0x114

        $sequence_5 = { 66833800 740c 0fb77202 83c202 6685f6 }
            // n = 5, score = 300
            //   66833800             | cmp                 word ptr [eax], 0
            //   740c                 | je                  0xe
            //   0fb77202             | movzx               esi, word ptr [edx + 2]
            //   83c202               | add                 edx, 2
            //   6685f6               | test                si, si

        $sequence_6 = { 8d85e8faffff 68???????? 50 ff15???????? 83c40c }
            // n = 5, score = 300
            //   8d85e8faffff         | lea                 eax, [ebp - 0x518]
            //   68????????           |                     
            //   50                   | push                eax
            //   ff15????????         |                     
            //   83c40c               | add                 esp, 0xc

        $sequence_7 = { 5d c3 8a55fa 80fa02 }
            // n = 4, score = 300
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   8a55fa               | mov                 dl, byte ptr [ebp - 6]
            //   80fa02               | cmp                 dl, 2

        $sequence_8 = { 50 8d85f4fdffff 50 c785f0fdffff05010000 ff15???????? 85c0 7513 }
            // n = 7, score = 300
            //   50                   | push                eax
            //   8d85f4fdffff         | lea                 eax, [ebp - 0x20c]
            //   50                   | push                eax
            //   c785f0fdffff05010000     | mov    dword ptr [ebp - 0x210], 0x105
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   7513                 | jne                 0x15

        $sequence_9 = { 8d85f0fcffff 50 8d85e8faffff 68???????? 50 ff15???????? }
            // n = 6, score = 300
            //   8d85f0fcffff         | lea                 eax, [ebp - 0x310]
            //   50                   | push                eax
            //   8d85e8faffff         | lea                 eax, [ebp - 0x518]
            //   68????????           |                     
            //   50                   | push                eax
            //   ff15????????         |                     

    condition:
        7 of them and filesize < 131072
}
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