Malicious PDF — malware analysis report

Static analysis result for SHA-256 cef63a42977c2757…

MALICIOUS

PDF

78.5 KB Created: 2021-09-18 12:21:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 3387807f2ae037aa047be4ba9114dd31 SHA-1: e752f221284c9482f444b0a992e909d45b9cbcbd SHA-256: cef63a42977c27576ea085fb3ad47f73f36f98fb325147612dffc836a70a412c
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on disposable domains and appear to be part of a link farm. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware delivery. While no scripts were explicitly extracted, the PDF structure and heuristic firings suggest it's designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://univerosg.com/ckfinder/userfiles/files/ropeluwamu.pdf In PDF document text
    • http://nieruchomosciklodzko.pl/files/file/xugugigefafupakefenubawuj.pdfIn PDF document text
    • http://myflora888.com/ck_files/files/56438573196.pdfIn PDF document text
    • https://www.leasing.net.in/ckfinder/userfiles/files/17366342427.pdfIn PDF document text
    • https://vanvoorst.info/uploaded/file/16646255857.pdfIn PDF document text
    • http://pbhdom.eu/userfiles/file/86659187625.pdfIn PDF document text
    • http://jjsgreatescape.com/uploaded_files/userfiles/files/lajebozo.pdfIn PDF document text
    • http://seoulgreeter.com/userData/board/file/wamesotutezufe.pdfIn PDF document text
    • https://eastmanllc.net/ckfinder/userfiles/files/74476803193.pdfIn PDF document text
    • https://autopsrus.com/ckfinder/userfiles/files/tawivegidijetibofudixe.pdfIn PDF document text
    • http://studiomedicoveterinariobellucci.eu/userfiles/files/88093714839.pdfIn PDF document text
    • http://longvu.vn/Images_upload/files/72076214363.pdfIn PDF document text
    • https://buka.ru/sadm_files/54811682963.pdfIn PDF document text
    • http://gazduire-domeniu.com/UserFiles/file/wuziju.pdfIn PDF document text
    • https://www.ideaklinikbakirkoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/161361d5799d28---31151686981.pdfIn PDF document text
    • http://simonhoirup.dk/userfiles/file/93883464591.pdfIn PDF document text
    • https://granitabrasive.hu/editor_up/21736857141.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=flutter+publish+play+storePDF 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_off0000cd84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD84 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e59b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE59B 10576 bytes
SHA-256: f2f5cdeb6ec3d114a01f010bd24b0d31489c84bcd33698b696c09f6aa887f8a1
font_02_sfnt_off0000fda7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDA7 18208 bytes
SHA-256: f23580cb74062f0f91cd5dd9d97f74805a98546d0746feb748121c73474b2562

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