Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4410c8c119822c3…

MALICIOUS

PDF

37.2 KB Created: 2020-03-07 17:13:49 +02:00 Authoring application: wkhtmltopdf 0.12.1.4 (via Qt 4.8.6) First seen: 2020-09-24
MD5: 99f28e53a3408c3b34d359d77c6a716d SHA-1: f1d1f37b2c03259fe0a271a6a209b361bf2f707f SHA-256: a4410c8c119822c3a3e33649eff3be7d8714a3e8046ce4e4662c47b49842d9ef
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The PDF contains a large number of external links, many of which point to other PDF files with numeric slugs. This pattern is indicative of a link farm or SEO manipulation tactic, potentially used to distribute malicious content or improve search engine ranking for harmful sites. The ML classifier strongly supports the malicious nature of this PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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 http://www.rhynotite.com/uploads/1/3/0/6/130620854/130620854.html#dilute+sulfuric+acid+safety+precautions PDF link annotation
    • http://daveparkercelebrant.com/uploads/1/3/0/5/130550698/vovanuzilizat.pdfIn PDF document text
    • http://nbarmichigan.com/uploads/1/3/0/2/130271171/makizupatovox.pdfIn PDF document text
    • http://djpalopionnerddjrzx.com/uploads/1/3/0/6/130639465/08aa3.pdfIn PDF document text
    • http://intermodelguatemala.com/uploads/1/3/0/7/130739239/6a11e8.pdfIn PDF document text
    • http://eca-engineering.com/uploads/1/3/0/4/130435893/bajajesokoliwojiga.pdfIn PDF document text
    • http://morganbrookfarm.com/uploads/1/3/0/5/130543546/84f9effd08.pdfIn PDF document text
    • http://wcd-up6fh3vz.mgh-r.ch/uploads/1/3/0/6/130621758/juvabo.pdfIn PDF document text
    • http://www.katedykstra.com/uploads/1/3/0/7/130740429/68e7620488.pdfIn PDF document text
    • http://mx.villageofnagogwoods.com/uploads/1/3/0/4/130488839/feditofaragekusugi.pdfIn PDF document text
    • http://dykewhistle.com/uploads/1/3/0/5/130545745/logeb.pdfIn PDF document text
    • http://boomboomloom.com/uploads/1/3/0/7/130739147/vanovuwusujegusat.pdfIn PDF document text
    • http://mensbetterhealth.com/uploads/1/3/0/6/130639545/bejewodisasojaz.pdfIn PDF document text
    • http://haccpinstruction.com/uploads/1/3/0/7/130776046/cacbfb3fca99.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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00006a8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6A8B 7492 bytes
SHA-256: 63623e2f3b10a18c4c19c15649d41f41d9d937d6af0065954f16fcf3a365660d