Malicious PDF — malware analysis report

Static analysis result for SHA-256 537f3e551542b9de…

MALICIOUS

PDF

84.0 KB Created: 2021-09-08 00:54:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: f518a61429a56575c9701984b54af94f SHA-1: dd5def89cf5c8abe1d14e397fc90932b25111980 SHA-256: 537f3e551542b9deb54f4859ae36c858cda05e74f115a534582b45b85ef58771
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites, indicating a link farm designed to redirect users to potentially malicious content. The ClamAV detection and ML classifier strongly suggest this PDF is malicious, likely serving as a lure for phishing or malware delivery. No scripts were extracted, and the document body was unreadable binary data.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 https://anzmrrn.org/wp-content/plugins/formcraft/file-upload/server/content/files/16091764fae3fd---jopoxupil.pdf In PDF document text
    • http://starcity-vinhomes.vn/app/webroot/img/files/vazenoxinalak.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/k2an5jndmo5cv2qkdkgmlbro25/ziwuviwiwazujiget.pdfIn PDF document text
    • https://www.ideaklinikkadikoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e4d474c5f30---2820635023.pdfIn PDF document text
    • https://minutesnap.com/wp-content/plugins/super-forms/uploads/php/files/ece5f07a6ae60e7be8eb49e5434a9947/68666986410.pdfIn PDF document text
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a014276dd9b---zukidaxevinebuputus.pdfIn PDF document text
    • http://filatelianumismaticaumbra.it/userfiles/file/bapovojogefegokone.pdfIn PDF document text
    • https://bfull.ru/uploads/files/munabawofupetebuxo.pdfIn PDF document text
    • https://toocapen.com/files/gasabudirakuvafexedatoxe.pdfIn PDF document text
    • https://wroclawmodelshow.pl/ckfinder/userfiles/files/wakorafora.pdfIn PDF document text
    • https://24emk.ru/ckfinder/userfiles/files/41373607618.pdfIn PDF document text
    • https://kalatranslation.co.uk/wp-content/plugins/super-forms/uploads/php/files/lpeed034deso43sugtg1ee0nvh/53402622364.pdfIn PDF document text
    • http://christembassydocklands.org/wp-content/plugins/super-forms/uploads/php/files/dac3e83c04fc1c9bf7795a8f9661b8fc/podomoribinesefis.pdfIn PDF document text
    • http://lawfirm.vn/MINH/user_files/file/fapubogofegurovanapin.pdfIn PDF document text
    • http://greenbiotech.vn/uploads/userfiles/file/nixokek.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac1adfccc15---xagatugigebibakunufu.pdfIn PDF document text
    • http://cuboni.com/uploadfile/hong202106271847472445.pdfIn PDF document text
    • http://nissanotogovap.vn/uploads/images/files/gipixobovufavuje.pdfIn PDF document text
    • https://www.accidentinjuryalbuquerque.com/wp-content/plugins/super-forms/uploads/php/files/5fiis27c17434mu2tvlak1mmfl/7290573439.pdfIn PDF document text
    • http://fortlauderdalelimorental.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b0009dd6d0a---66744819827.pdfIn PDF document text
    • https://aquarell.ro/userfiles/file/27570595835.pdfIn PDF document text
    • http://senn60reunion.com/clients/876260/File/88140625247.pdfIn PDF document text
    • http://guides2alpes.fr/uploads/file/33764403708.pdfIn PDF document text
    • https://turismopontevedra.com/ckfinder/userfiles/files/59324574226.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=chicago+manual+style+footnote+for+websitePDF 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_off0000e0a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0A6 18232 bytes
SHA-256: ba82d3f17d80fc3dbacfc3c26da43dc2a25dc6d608d87ad0de850be56de427aa
font_01_sfnt_off00010fef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FEF 11252 bytes
SHA-256: 23ba50428513dba72f38c28b889d3b1cdd547ea4cf68b3ba5cb6131e495252dd
font_02_sfnt_off00012a4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A4E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1