Malicious PDF — malware analysis report

Static analysis result for SHA-256 b527e246afd09ba6…

MALICIOUS

PDF

131.3 KB Created: 2021-10-16 15:12:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 96c5a43650774241a4e061970d419146 SHA-1: 03fec8b9d710233f3a136d964e8edc23142c074b SHA-256: b527e246afd09ba6221c12b10879a71140e8366d32bcd741f433b666a1bec9f1
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple disposable or compromised domains, likely for phishing or malware delivery. The presence of external URIs and link farm characteristics strongly suggests an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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 http://thuaphatlailongthanh.com/upload/contentFile/minhchau/file/4351510452.pdf In PDF document text
    • http://ty6600.com/userfiles/file/14387622812.pdfIn PDF document text
    • http://westfallassociates.com/documents/file/40136467008.pdfIn PDF document text
    • http://flamefitnessstudio.com/cewit/images/file/67529562229.pdfIn PDF document text
    • https://ssmahavidyalaya.org/lion/uploadedfiles/fck/files/file/sapozanewex.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1615e9100e8e09---16359969561.pdfIn PDF document text
    • https://www.projectorrentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614d98eeb21bd---levufuxutowivufipuxebobaz.pdfIn PDF document text
    • http://lubrifianti-auto.ro/files/file/suwisavezizaweza.pdfIn PDF document text
    • https://radekslodkiewicz.pl/files/file/rulaxoravumudabuje.pdfIn PDF document text
    • http://www.tekkoo.net/images/library/File/64768557324.pdfIn PDF document text
    • http://career-id.org/ckfinder/userfiles/files/sonenatujitudoxoxulilemes.pdfIn PDF document text
    • http://pacemakerpressintl.com/uploads/assets/file/85293440564.pdfIn PDF document text
    • http://szsahsh.com/uploads/files/52392200616.pdfIn PDF document text
    • http://pijntherapie.be/uploads/files/45212601370.pdfIn PDF document text
    • https://kildevangen.dk/files/40948522792.pdfIn PDF document text
    • http://reichspfarrer.sk/file/bagaza.pdfIn PDF document text
    • https://gerbangkuis.com/contents/files/99693186152.pdfIn PDF document text
    • http://sochi-riba.ru/ckfinder/userfiles/files/64139137353.pdfIn PDF document text
    • http://tamker.hu/userfiles/file/nitosadivara.pdfIn PDF document text
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1615004f9ac60b---lokam.pdfIn PDF document text
    • https://huaku3c.tw/uploads/files/202110010452285265.pdfIn PDF document text
    • https://hattshopping.com/admin/assets/images/ckfiles/nufibudipatizesatefalim.pdfIn PDF document text
    • https://liur-krd.ru/userfiles/file/75144766668.pdfIn PDF document text
    • https://jaukiaplinka.lt/ckfinder/userfiles/files/40913291054.pdfIn PDF document text
    • http://ducthoaudio.com/upload/files/5607564829.pdfIn PDF document text
    • http://feedproxy.google.com/~r/Xvkpad/~3/896FEnmJZlk/uplcv?utm_term=computer+science+an+overview+chapter+review+answersPDF link annotation
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000199c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x199C6 20216 bytes
SHA-256: ac4f0bf4a5f18a78bf5253835ff76e2c64e35cc3076511bee02b5f42e5e25271
font_01_sfnt_off0001cda3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1CDA3 10876 bytes
SHA-256: fd6ae39252b787f5d9a53c957600e172eee48af05f8fd526fda33a46d939d9af
font_02_sfnt_off0001e6b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1E6B3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1