Malicious PDF — malware analysis report

Static analysis result for SHA-256 73fdb62275ce0673…

MALICIOUS

PDF

106.4 KB Created: 2021-09-05 11:45:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 8f259fc78fe6befb3663ba25e0ec7363 SHA-1: fdd5fd784502516d269bf605b23ec82b34237673 SHA-256: 73fdb62275ce06738648facf79bdb64d986b538a57f6bdef4c441cc5fbac5ade
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm pointing to compromised WordPress uploads and potentially disposable hosting. The embedded URLs, despite some being marked benign, suggest an attempt to redirect users to malicious content. The PDF structure itself does not contain readable content, indicating it's likely a container for malicious links or exploits.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://amako-ra.com/wp-content/plugins/super-forms/uploads/php/files/3b393a7cea0997c980cb8587d8ecd2ec/84589785624.pdf In PDF document text
    • http://daehwa.info/uploaded/file/nusiwikasumiveduvunajab.pdfIn PDF document text
    • https://dintek.eu/uploads/file/17257647615.pdfIn PDF document text
    • https://www.mozartcantat.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161000521b64cb---xodifufazavuton.pdfIn PDF document text
    • http://moveisgarciadigital.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1611e863a6ecd2---wijuxezuw.pdfIn PDF document text
    • http://worthingtonpark101.com/userimages/poxuwavojij.pdfIn PDF document text
    • https://monyetjoget.com/contents//files/24780957285.pdfIn PDF document text
    • http://zuche0551.com/upload/file/35405537542.pdfIn PDF document text
    • http://antichigelsi.it/userfiles/files/gonez.pdfIn PDF document text
    • https://megalightgroup.lv/uploads/files/tozusumogepomi.pdfIn PDF document text
    • https://petala.gr/userfiles/file/kifoluf.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610b45acb3949---falifef.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b88ca64ba48.pdfIn PDF document text
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/je6433tqjlddvmjookkqf8j0v2/tarokuloxabidubik.pdfIn PDF document text
    • https://masini-de-ambalat.ro/images/userfiles/82942332642.pdfIn PDF document text
    • https://dbjadow.pl/attachments/file/kokivasivusujolexanajej.pdfIn PDF document text
    • https://fibaquitaine.fr/cebatrama/userfiles/files/xasijobaxokefuwiko.pdfIn PDF document text
    • http://randoquad72.fr/userfiles/file/vakowopobiru.pdfIn PDF document text
    • http://smflow.in/admin/uploads/file/tibelazaj.pdfIn PDF document text
    • http://cuatudongnhatrang.com/uploads/files/91242089862.pdfIn PDF document text
    • https://seikico.net/img-tym/files/42951818816.pdfIn PDF document text
    • http://mgocsm.in/userfiles/file/86848045348.pdfIn PDF document text
    • http://www.annaleehuber.com/content_files/file/77494726364.pdfIn PDF document text
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a4bb5a84b9f---54435108965.pdfIn PDF document text
    • http://biswasi.com/userfiles/files/kikafafinagawupafab.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=qpsk+modulation+pdfPDF 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_off00013526.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13526 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00014d38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14D38 20972 bytes
SHA-256: b889d98af9f1cc1efc56a77f61c1606819a7425df29173b00f2aabb1e5b757eb
font_02_sfnt_off00018337.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18337 10680 bytes
SHA-256: fd7e4c1bfc453d0e15e12ea0bc5ff21378f31d922d6a0d7d5ac8fdf4de0e59ee