Malicious PDF — malware analysis report

Static analysis result for SHA-256 fc4331f6e8ae3274…

MALICIOUS

PDF

68.0 KB Created: 2021-04-16 18:10:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 4f0b9b2e91d4e3c84a1c7dc4455512f1 SHA-1: e63e398f0fcec92a381ffc02936d9dad09357784 SHA-256: fc4331f6e8ae3274367c665fe391268d0d354aea020a1d66166dc28d3bba438d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file is a PDF document identified as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to PDF files hosted on various domains, suggesting a link farm or phishing lure. The document body, though heavily obfuscated, appears to be a recipe, likely a pretext to disguise the malicious nature of the PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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 https://www.termis.org/system/files/webform/776381217.pdf In PDF document text
    • https://www.woonsocketri.org/system/temporary/webform/kebadewanizokodijixupid.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/90877516301.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/46846662681.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/tekuxegejarikuferibo.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/doxuwekuwazomiloxeri.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/padubomi.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/vojowavujelosapol.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/21073527915.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/1232685222.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/88462653206.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/gafazibo.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/27880179426.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=how+to+rotisserie+a+chicken+in+an+air+fryerPDF link annotation
    • https://thesanfordschool.asu.edu/sites/default/files/webform/moxogugudufagelo.pdfIn PDF document text
    • https://gradfutures.princeton.edu/system/files/webform/fumegefexuwonadijot.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ce88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE88 5156 bytes
SHA-256: ecb7823ec40cbbfe7188f384f175447f036c9b62111f64353a51d51f006a16fe
font_01_sfnt_off0000e024.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE024 10240 bytes
SHA-256: 9a87797cc431601f797378424411dbd0b33f349aeb243a3d6ecdb07b1976ab14