Malicious PDF — malware analysis report

Static analysis result for SHA-256 442777aae4938aa4…

MALICIOUS

PDF

72.5 KB Created: 2021-03-30 07:04:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-15
MD5: 1d4e846bb8c32f98caaa743da40f9f96 SHA-1: dfa2808085e62b94e5654f9cb1e166457a6949f5 SHA-256: 442777aae4938aa4a87034d68241d82b97e0a34d32190857aa7aefe79d2ab0d8
134 Risk Score
Tags
free-cdn-ebook-manual-lure

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external URIs, many hosted on disposable domains, suggesting a link farm designed to redirect users. The presence of a 'download button' heuristic further supports the lure-based attack pattern. While no scripts were explicitly extracted, the PDF structure and external links indicate an attempt to download and execute a secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://jacksth.ru/123?utm_term=joint+handwriting+worksheets PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4405197/normal_602a3cc8f1c3d.pdfIn PDF document text
    • https://vobiromab.weebly.com/uploads/1/3/4/6/134653190/wakeniv.pdfIn PDF document text
    • https://xowilululevala.weebly.com/uploads/1/3/4/0/134017879/10399e54ad18.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4377113/normal_5fd344b18c603.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4423166/normal_5fc5e589bf15c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4367645/normal_605faec550816.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369912/normal_603b182a18f11.pdfIn PDF document text
    • https://debarinibew.weebly.com/uploads/1/3/0/7/130775297/703413.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/wupiwupiwot/zipofaxesedutusuxiji.pdfIn PDF document text
    • https://s3.amazonaws.com/jeworurowam/nojokudoxukakigi.pdfIn PDF document text
    • https://b3a8b944-ddec-4d17-9b53-5a1c05c66d8c.filesusr.com/ugd/314503_1d3feddf385b41e5879d9b2289afe4af.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/d2565b93-5149-43fa-a771-ea81b26e226c/55169651275.pdfIn PDF document text
    • https://s3.amazonaws.com/jagux/aphasia_book_free.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ef31fac0-d9df-4fb2-a91e-2280dafa4fc7/how_to_adjust_ultegra_di2_rear_derailleur.pdfIn PDF document text
    • https://s3.amazonaws.com/silubebebefuju/clasificacin_de_las_cuentas_del_balance_general.pdfIn PDF document text
    • https://113c517c-d7b0-4b36-99d7-6722bcb7ef36.filesusr.com/ugd/8e66a5_0d7e3d15fa1c4701b47bd90082fb81dd.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/275fafd7-cc3d-4bac-b7df-9b358c6866e5/zaturedoperefapigovobavob.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_off0000daa5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAA5 5200 bytes
SHA-256: 905c6102ae799033e997aae1e6526c8db5ed2829e0a44c56a73ce39d7c6ad770
font_01_sfnt_off0000ec62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC62 11708 bytes
SHA-256: 18f5b327ddae0af84c8f8fb187b0182ed8eaf7e2da98be0d3de71ff5a5729f91

Open this report in the interactive analyzer, or submit your own file for analysis.