Ursnif — Office (OOXML) malware analysis

Static analysis result for SHA-256 87c977b6682f989d…

MALICIOUS

Office (OOXML)

347.6 KB Created: 2021-06-26 16:20:00 UTC Authoring application: Microsoft Office Word 16.0000
MD5: 6823de390080464401c9f787ec8cdc25 SHA-1: ff088c896ff0239a8d5b263efc2c65957196f4bd SHA-256: 87c977b6682f989dd52a43ed423393279ff8ab8ea97e03ea7c2862c91eabe6d3
282 Risk Score

Malware Insights

Ursnif · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1566.001 Spearphishing Attachment

The sample contains a VBA macro with an AutoOpen subroutine that utilizes the Shell() function, indicating it's designed to execute arbitrary commands. ClamAV detections confirm this is a known Ursnif dropper variant. The macro likely downloads and executes a second-stage payload, a common tactic for this malware family.

Heuristics 7

  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • ClamAV: Doc.Dropper.Ursnif-6864686-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Ursnif-6864686-0
  • 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.
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • 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
  • 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://schemas.microsoft.com/office/word/2010/wordprocessingCanvas
    • http://schemas.microsoft.com/office/drawing/2014/chartex
    • http://schemas.microsoft.com/office/drawing/2015/9/8/chartex
    • http://schemas.microsoft.com/office/drawing/2015/10/21/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/9/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/10/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/11/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/12/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/13/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/14/chartex
    • http://schemas.openxmlformats.org/markup-compatibility/2006
    • http://schemas.microsoft.com/office/drawing/2016/ink
    • http://schemas.microsoft.com/office/drawing/2017/model3d
    • http://schemas.openxmlformats.org/officeDocument/2006/relationships
    • http://schemas.openxmlformats.org/officeDocument/2006/math
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawing
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawing
    • http://schemas.openxmlformats.org/wordprocessingml/2006/main
    • http://schemas.microsoft.com/office/word/2010/wordml
    • http://schemas.microsoft.com/office/word/2012/wordml
    • http://schemas.microsoft.com/office/word/2018/wordml/cex
    • http://schemas.microsoft.com/office/word/2016/wordml/cid
    • http://schemas.microsoft.com/office/word/2018/wordml
    • http://schemas.microsoft.com/office/word/2020/wordml/sdtdatahash
    • http://schemas.microsoft.com/office/word/2015/wordml/symex
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroup
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInk
    • http://schemas.microsoft.com/office/word/2006/wordml
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShape

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
c0679bc74e92b6b8ddfb97cb35e7c6373bf67ea4d15a03db53420ec5ef9eb8c6
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 4448 bytes
vbaProject_00.bin
1a0bcc0cb592e0cd2e29139b1add403037776babb925513464549991058a1a31
vba-project OOXML VBA project: word/vbaProject.bin 30208 bytes
Detection
ClamAV: Doc.Dropper.Ursnif-6864686-0
Obfuscation or payload: unlikely