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

Static analysis result for SHA-256 055c3b690cfa6797…

MALICIOUS

Office (OOXML) / .XLSX

830.2 KB Created: 2022-05-16 17:34:45 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2023-07-10
MD5: affde6cd92ad047bfb42554e85709eab SHA-1: a599af211bd4aa91a58cfcf3abe10f283f3d493c SHA-256: 055c3b690cfa67978db3760cc7d7ffef3bacb90bda7bf31b8c5e318b575829a0
180 Risk Score

Malware Insights

Xls.Downloader.Trojan-aa0b8f388d8573cd · confidence 95%

MITRE ATT&CK
T1204 Malicious File Execution T1204.002 Malicious File Execution: User Execution: Malicious File T1566 Phishing T1566.001 Phishing: Spearphishing Attachment

The file is an Excel document containing an embedded Equation Editor OLE object, which is a known vector for exploiting CVE-2017-11882. This vulnerability allows for the execution of arbitrary code, typically used to download and run a secondary malicious payload. The ClamAV detection name 'Xls.Downloader.Trojan-aa0b8f388d8573cd' further supports its role as a downloader.

Heuristics 4

  • CVE-2017-11882 — Equation Editor FONT record overflow critical CVE likely CVE_2017_11882
    Equation Editor MTEF contains an overlong FONT typeface field, the vulnerable copy primitive for CVE-2017-11882. This is stronger evidence than the Equation Editor CLSID alone because it identifies the malformed record that drives code execution in EQNEDT32.EXE.
  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/Zzvi1g.abc 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
  • Embedded OLE object medium OOXML_OLE_OBJECT
    Document contains an embedded OLE object

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
ooxml_oleobject_00.bin
23b419ef9d588c9790ef5cad36c6779abc7b2a2f844a9b07cb9a42162f86c46d		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/Zzvi1g.abc 972800 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.