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

Static analysis result for SHA-256 5c1274a89a882c45…

MALICIOUS

Office (OLE) / .XLS

2.61 MB Created: 2020-09-16 17:35:23 First seen: 2023-05-19
MD5: 558a45d249853d03345e6f8a1109e681 SHA-1: 2c710d503f26bf9467d6655d12979c4451f26df1 SHA-256: 5c1274a89a882c457af5e725f0058e9013358f34c3f4bc66c66a8c77690ba999
442 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1059.001 PowerShell T1204.002 Malicious File T1566.001 Spearphishing Attachment T1105 Ingress Tool Transfer

The sample is a macro-enabled Excel file that triggers malicious activity upon opening via the Workbook_Open event. It utilizes WScript.Shell and CreateObject to execute obfuscated VBA code, strongly indicating an intent to download and execute a secondary payload. The presence of a Shell() call and WScript.Shell usage points to the execution of external commands or scripts.

Heuristics 11

  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
  • Obfuscated auto-exec VBA loader critical OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER
    Auto-exec VBA reconstructs strings with a heavy custom decoder (numeric char-array, repeated hex-string decode, or junk-token Replace removal) and feeds them to a COM-instantiation or execution sink. This obfuscated-loader shape keeps CreateObject/Shell/URL indicators out of the macro source.
  • Reference to Windows Script Host high SC_STR_WSCRIPT
    Reference to Windows Script Host
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • GetObject call high OLE_VBA_GETOBJ
    GetObject 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
  • 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://www.frez.co.uk

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
0655780afdc3d12ea8ab3e83abc4b9374cbaa9766cf9d3ca1b14d9310ce1e07f
vba-macro oletools.olevba.extract_macros (decoded VBA source) 2221184 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).