Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 b65566e05d887d80…

MALICIOUS

Office (OOXML)

26.4 KB Created: 2021-08-18 02:04:39 UTC Authoring application: Microsoft Excel 16.0300
MD5: 3d45c1f829da8263ca4b3333abc0517c SHA-1: 17ae7e09a2c19c5d146aeacbed82204425e2f8a6 SHA-256: b65566e05d887d80c9caca129f483f805d298f709ef20874eac095c19c458da6
610 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1105 Ingress Tool Transfer T1204.002 Malicious File

The sample contains VBA macros that execute upon opening, leveraging WScript.Shell and CreateObject to download a second-stage payload from a hardcoded URL. The script then saves the downloaded content to disk as 'Details.dat' and 'LeakDetails.dat' in the temporary directory, indicating an attempt to execute further malicious code. The document body content, referencing 'Password Leaked', serves as a lure to trick the user into interacting with the malicious content.

Heuristics 14

  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
  • Obfuscated VBA Shell command with URL critical OLE_VBA_OBFUSCATED_SHELL_URL
    VBA macro invokes Shell with command text assembled through decoder or string-manipulation functions and includes a URL. This is a high-confidence downloader/dropper pattern, stronger than Shell or URL evidence on their own.
  • VBA WMI Win32_Process launcher critical OLE_VBA_WMI_PROCESS_CREATE
    VBA macro builds or references a WMI moniker for Win32_Process and invokes .Create to start a command. This is a high-confidence macro execution chain that often hides the WMI class name through string concatenation or helper functions.
  • VBA downloads and writes a file to disk critical OLE_VBA_HTTP_DROP_EXEC
    VBA reads an HTTP response body and writes it to disk (ADODB.Stream SaveToFile). Combined with the auto-exec/Shell paths this is a download-drop dropper even when the COM ProgIDs are built dynamically to evade keyword scanning.
  • ClamAV: Doc.Downloader.Valyria-10026858-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Valyria-10026858-0
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • Auto_Open macro high OLE_VBA_AUTO
    Auto_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.
  • VBA project inside OOXML medium OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
  • 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://ec2-18-184-17-12.eu-central-1.compute.amazonaws.com/standardchartered/passleak/180821/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
1cbfcded1b86d20c6f05a8dd13d479335b01c5dedb40b7a80900eed07d182383
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 4717 bytes
vbaProject_00.bin
5992f97af3643038923844f1d84a2c6e21383bc226c632a5563bcb9ac9f5cd34
vba-project OOXML VBA project: xl/vbaProject.bin 18432 bytes
Detection
ClamAV: Doc.Downloader.Valyria-10026858-0
Obfuscation or payload: unlikely