Malicious PDF — malware analysis report

Static analysis result for SHA-256 9fb5ef3915f8ee36…

MALICIOUS

PDF

72.7 KB Created: 2021-04-17 17:19:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: cff358ccad9f0990cc4a28d417d37792 SHA-1: 9060fd670330d86ee366f4bfc6e2bd1bd46ae15e SHA-256: 9fb5ef3915f8ee36bb0d0ce009d5962ceb09ed7d8e4601227328cfa3da8212f0
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample is a PDF document flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. It contains numerous embedded URLs, many of which point to potentially compromised or disposable domains, suggesting a link farm or phishing attempt. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this. While no scripts were explicitly extracted, the nature of the embedded URLs and the overall detection profile strongly suggest an attempt to redirect the user to a malicious site, likely for credential harvesting or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://vectorcorp.net/sites/default/files/webform/resume/dufovomajaxavekasodulep.pdf In PDF document text
    • https://www.ofalloncasting.com/sites/default/files/webform/66890294103.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/90877516301.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/minokoniniwige.pdfIn PDF document text
    • http://pilgrimland.com/sites/default/files/webform/resume-uploads/jokefogebefuzifuzew.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/89382212171.pdfIn PDF document text
    • https://www.afscme65.org/system/files/webform/rerezuduzolorefa.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/bavowusakixonodokuja.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/nojezajewi.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/gafazibo.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/69174909787.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/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=que+es+el+lider+positivoPDF link annotation
    • https://minorsoncampus.princeton.edu/system/files/webform/fujixedapilevunagujos.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_off0000dfda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFDA 4864 bytes
SHA-256: a3ed726c78528212999fb8945dbe40998e6c40d4d6853fe3cebaf503d220d583
font_01_sfnt_off0000f078.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF078 11608 bytes
SHA-256: a7b84cfb6b8cec41ccff9335cb2336640a64a94b6225aeca73dc97778d4c5169