Malicious PDF — malware analysis report

Static analysis result for SHA-256 d43f37b61751f41b…

MALICIOUS

PDF

74.7 KB Created: 2021-06-23 00:44:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 6d61cf4a22cc61cc37699f8f0acc3580 SHA-1: f72881d6fdbcbd7ae731a9ce818d7cd936dd9036 SHA-256: d43f37b61751f41bf49d545ef16825f2ccbb0dd87d8b7ffd5eb359fec8189799
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics suggest it functions as a link farm, potentially for SEO manipulation or to host further malicious content, with numerous links pointing to various domains, some of which appear to be compromised CMS uploads. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a phishing or malicious content delivery attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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://niestachow.pl/data/aktualnosci_imgs/file/furesexudopojixu.pdf In PDF document text
    • http://nage-z.com/ckfinder/userfiles/files/puzosare.pdfIn PDF document text
    • https://dusunceokulu.net/resimler/files/fubiz.pdfIn PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5d912dc09c---26008501537.pdfIn PDF document text
    • http://chonburi33.com/userfiles/file/20942235343.pdfIn PDF document text
    • https://licorne-hotel-restaurant.com/userfiles/file/90582675747.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/830909743ba863a706acd2ead88e77cc/60800905388.pdfIn PDF document text
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/01acc7e0a4308b420c9d9b3a8553b497/tovovikisokananuj.pdfIn PDF document text
    • https://militarynetwork.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608d4a08c0117---24376165344.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084d48bf1806---wifoxadifuloso.pdfIn PDF document text
    • http://profisystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609e49c16e544---81370998757.pdfIn PDF document text
    • http://www.grundys.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608aa2e0c9df9---44799577301.pdfIn PDF document text
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/16078e0b7ecdf6---bopobiti.pdfIn PDF document text
    • http://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afe53da541f---29939528048.pdfIn PDF document text
    • http://www.lavalledesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cad271c212a---bagivazuxuretom.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=medicinal+chemistry+books+for+pharmacy+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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e3db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3DB 5704 bytes
SHA-256: b41546a08263224e4e1f7ee7aa62bfb3609a3c6ffb111b72e162a79b5c8502f2
font_01_sfnt_off0000f723.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF723 11812 bytes
SHA-256: 7911f9a89b15fc8d1146b985a8077734c5c3acfc944776edab3cdbfe1e49a881