Xls.Downloader.Trojan-aa0b8f388d8573cd-aa0b8f388d8573cd-9950439-0 — Office (OOXML) / .XLSX malware analysis

Static analysis result for SHA-256 a71eec60361ea97b…

MALICIOUS

Office (OOXML) / .XLSX

830.7 KB Created: 2022-05-16 17:34:45 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2022-06-01
MD5: 09a7153f63a29e80bb7d2c698133d714 SHA-1: d080f77215d255a44230ecfb2c8028b5720add2c SHA-256: a71eec60361ea97b8cefe6ebdc04a1fa77dbcccf6ea0f4dbdaa4ec0f9657fd7e
160 Risk Score

Malware Insights

Xls.Downloader.Trojan-aa0b8f388d8573cd-aa0b8f388d8573cd-9950439-0 · confidence 95%

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious File

The sample is an Excel document containing an embedded OLE object identified as an Equation Editor. This object exhibits anomalies in its Ole10Native stream size and entropy, strongly suggesting it carries a malicious payload. ClamAV detection confirms this, identifying it as 'Xls.Downloader.Trojan-aa0b8f388d8573cd-aa0b8f388d8573cd-9950439-0'. The presence of these indicators points to a spearphishing attachment attack vector designed to deliver a downloader trojan.

Heuristics 4

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/ANDZI.CJBc9 contains the Equation Editor CLSID, the legacy component exploited by CVE-2017-11882, CVE-2018-0802, and CVE-2018-0798.
  • ClamAV: Xls.Downloader.Trojan-aa0b8f388d8573cd-aa0b8f388d8573cd-9950439-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Trojan-aa0b8f388d8573cd-aa0b8f388d8573cd-9950439-0
  • Equation Editor object carries payload-like Ole10Native stream high OLE_EQUATION_OLE10NATIVE_PAYLOAD_ANOMALY
    Embedded OLE object declares the Equation Editor CLSID but stores a large high-entropy Ole10Native stream with malformed package sizing. This is an exploit-shaped Equation/OLE payload container seen in malicious OOXML samples. It is not assigned to a specific CVE unless the MTEF/Equation Native primitive also matches.
  • Embedded OLE object medium OOXML_OLE_OBJECT
    Document contains an embedded OLE object

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
ooxml_oleobject_00.bin
a52a14b40ab46453ce5202bac5f788dd4c0bf7b30582641e239de21be73cc7a4		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/ANDZI.CJBc9 983040 bytes
ooxml_oleobject_00_ole10native_00.bin
9c53d5beca66a4b9f46402aeaf7ab219948f47ca6f09f72a006d8f083a168abb		 ole-package OOXML xl/embeddings/ANDZI.CJBc9 Ole10Native stream: Ole10NatIVE 973016 bytes
emf_00.emf
38f17a599ac5d645df3840bbb401710ef81573a747da20abbfc1b7d9a9273b58		 ooxml-emf OOXML EMF part: xl/media/image1.emf 169096 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.