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

Static analysis result for SHA-256 bdf9a0619a55899f…

MALICIOUS

Office (OLE) / .XLS

278.0 KB Authoring application: Microsoft Excel
MD5: 530f45d0cae00ebbc93c3a9e802e7943 SHA-1: 6d3543305a22014a5e4dc15aec0e13043dcd3cb3 SHA-256: bdf9a0619a55899f98c4f757561926fe4ddb292ff3d596c44467898ed0af8df7
180 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.002 Spearphishing Attachment

The file is an Excel spreadsheet containing VBA macros, indicated by the OLE_VBA_MACROS and OLE_VBA_AUTO heuristic firings. The presence of an Auto_Open macro suggests the code executes automatically when the document is opened. The DOC BODY contains a string that appears to be a prompt for a password, suggesting a credential harvesting or phishing attempt. The OLE_SLACK_ANOMALY and EXTRACTED_FILE_STATIC_TRIAGE heuristics further indicate suspicious content within the OLE structure.

Heuristics 5

  • OLE document has large unaccounted-for region high OLE_SLACK_ANOMALY
    OLE file is 284,672 bytes but its declared streams total only 95,683 bytes — 188,989 bytes (66%) 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).
  • Auto_Open macro high OLE_VBA_AUTO
    Auto_Open macro
  • Auto_Close macro high OLE_VBA_AUTOCLOSE
    Auto_Close macro
  • 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
8107cc1c5a3756ad06aea6673157e205a68d382a83bd146406dad19c51b52ae6
vba-macro oletools.olevba.extract_macros (decoded VBA source) 45660 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 10 Chr/ChrW string-construction calls.