Malicious Office (OLE) / .XLS — malware analysis report

Static analysis result for SHA-256 a885ee7084261dd6…

MALICIOUS

Office (OLE) / .XLS

1.73 MB Created: 2004-11-02 08:19:39 Authoring application: Microsoft Excel
MD5: d2f35407254a8294bdf47c820046831e SHA-1: c39c2ddc39f0dcea1388cb7209a9626434c4ee57 SHA-256: a885ee7084261dd609d40850b198d9344bf5c2eafcbd9434f322ecc24b7f46e1
220 Risk Score

Malware Insights

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

The file is an Excel spreadsheet containing a large VBA macro. Heuristics indicate the presence of a Workbook_Open or Auto_Open macro, which is commonly used to execute malicious code upon opening the document. The macro utilizes CreateObject and exhibits VBA Chr string obfuscation, suggesting it's designed to download and execute a second-stage payload. The presence of 'macros.bas' as an extracted artifact further supports this.

Heuristics 6

  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • Auto_Open macro high OLE_VBA_AUTO
    Auto_Open 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.
  • Suspicious extracted artifact high 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.
  • VBA macros detected medium OLE_VBA_MACROS
    Document contains VBA macro code

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
48a04751a5d4364beb6be6ec8f2be4cddff6b810d1ece71188c778199ced6140
vba-macro oletools.olevba.extract_macros (decoded VBA source) 188613 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 40 Chr/ChrW string-construction calls. Carved macro source contains an auto-exec entry point and execution/download terms.