Malicious PDF — malware analysis report

Static analysis result for SHA-256 c77fbdacca07f28d…

MALICIOUS

PDF

72.1 KB Created: 2021-05-31 23:54:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-30
MD5: 56da035b54ed8e6e4cc0e968a6b07637 SHA-1: ef15859194f8b15a9328b41896e0ac2ad92a5a4b SHA-256: c77fbdacca07f28dc32586f3e6a8bba408fefe8a673d5274ab1127b3f0411bd4
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many hosted on disposable domains, suggesting a link farm or SEO spam operation. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and numerous external links point towards an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • 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 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.
  • 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://chcial.ru/pbw?utm_term=which+letters+are+ascenders+and+descenders PDF link annotation
    • https://nomozusosowewox.weebly.com/uploads/1/3/1/4/131453154/jofudutuxarozew-rugataronarujam.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4414174/normal_6063ae335c7a4.pdfIn PDF document text
    • https://lezogujivezubix.weebly.com/uploads/1/3/4/8/134878846/3853516.pdfIn PDF document text
    • https://sarotokatot.weebly.com/uploads/1/3/2/6/132682281/6567954.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4445104/normal_605b4bef8c07c.pdfIn PDF document text
    • https://bitebizato.weebly.com/uploads/1/3/4/5/134583528/62b95ad5.pdfIn PDF document text
    • https://fozuwojomawunuk.weebly.com/uploads/1/3/0/7/130776264/8308011.pdfIn PDF document text
    • https://tavigawatogup.weebly.com/uploads/1/3/5/3/135389884/vemakofafus.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4388841/normal_5fcbca2cd474a.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4393204/normal_600109d8d8801.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4492901/normal_60afe30220f06.pdfIn PDF document text
    • https://gawejewigedek.weebly.com/uploads/1/3/2/7/132741035/zosorer-linigasedisa-pujubod.pdfIn PDF document text
    • https://jefamozalubibul.weebly.com/uploads/1/3/1/4/131438275/39f92.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4374851/normal_5fd0821f53dd6.pdfIn PDF document text
    • https://suvuleje.weebly.com/uploads/1/3/4/8/134871599/gevekiniforiluzipop.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://poxanoralanu.pbworks.com/w/file/fetch/144426225/dakifufabalanutudu.pdfIn PDF document text
    • http://xojifot.pbworks.com/w/file/fetch/144426669/zoriku.pdfIn PDF document text
    • http://fufitiruw.pbworks.com/w/file/fetch/144426615/plantronics_voyager_3200_manual.pdfIn PDF document text
    • http://tagexoba.pbworks.com/f/wivesamufax.pdfIn PDF document text
    • http://jesababa.pbworks.com/f/cuantos_ejes_de_simetria_tiene_triangulo.pdfIn PDF document text
    • http://wuvebag.pbworks.com/f/lefepug.pdfIn PDF document text
    • http://papoxuva.pbworks.com/w/file/fetch/144422157/koreforuvopawi.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_off0000dda3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDA3 5040 bytes
SHA-256: e83ca089727e5587fd8176a8c73a1d0360893593e1a8ea82b6cc31d3c4378681
font_01_sfnt_off0000eecc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEECC 10708 bytes
SHA-256: 10092325c0795aa8597002dde7bf2b51077bc59151cab247b9902b7fad263f38