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

Static analysis result for SHA-256 8f4bca3c62268fff…

MALICIOUS

Office (OLE) / .XLS

256.0 KB
MD5: f8d9b7c864fb7558e8bad4cfb5c8e6ff SHA-1: a45ab1a9dec488278ee9682735d42d61dfc38b9e SHA-256: 8f4bca3c62268fff0458322d111a511e0bcfba255d5ab78c45973bd293379901
148 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1204.002 Malicious File

The presence of VBA macros and a CreateObject call strongly suggests malicious intent. The CreateProcess API reference indicates the macro attempts to launch an external process. The large slack space in the OLE document is also a common characteristic of macro-laden malicious files. Without further script analysis, the exact payload and delivery mechanism remain unclear, but the overall pattern points to a macro-based downloader.

Heuristics 5

  • Reference to CreateProcess API high SC_STR_CREATEPROCESS
    Reference to CreateProcess API
  • OLE document has large unaccounted-for region high OLE_SLACK_ANOMALY
    OLE file is 262,144 bytes but its declared streams total only 125,786 bytes — 136,358 bytes (52%) 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).
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • VBA macros detected medium OLE_VBA_MACROS
    Document contains VBA macro code
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
6604b7b9c0d7f0d7004090e793d434134188b53602545ad435e96792c1a214ea
vba-macro oletools.olevba.extract_macros (decoded VBA source) 219113 bytes