Malicious PDF — malware analysis report

Static analysis result for SHA-256 df51a9d00b47cdce…

MALICIOUS

PDF

87.7 KB Created: 2021-09-16 09:24:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 43a129d4e5985ccc2c8e677a0d2f65ef SHA-1: be997eaf71fbd2a29790ee13559a971a62379722 SHA-256: df51a9d00b47cdcee48330026fd47937c85d298814ec37b19bf021e357b708bf
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to potentially compromised websites or disposable hosting, indicating a link farm or phishing attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded links are indicative of techniques used to redirect users to malicious sites, potentially for further exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://neapol-m.ru/usr/file/wuzexerodi.pdf In PDF document text
    • https://jungleflightchiangmai.com/Uploads/files/xowolafopitesexobemin.pdfIn PDF document text
    • http://cokhihoangvinh.com/uploads/userfiles/file/zogev.pdfIn PDF document text
    • http://baheth24aqari.com/ckfinder/userfiles/files/gemuzabenatuzasil.pdfIn PDF document text
    • http://ipea.kr/userData/board/file/52231555141.pdfIn PDF document text
    • http://mrcubezpieczenia.pl/app/webroot/media/files/gejixixamenavorakinaseb.pdfIn PDF document text
    • http://bjhtdszdh.com/v15/Upload/file/202191011191012.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131be3fc477e---kerojakesalogigaror.pdfIn PDF document text
    • https://masterjobintl.com/ckfinder/userfiles/files/bimakaviwidufodelitov.pdfIn PDF document text
    • https://bobecoingatlan.com/uploads/editor/file/62817234370.pdfIn PDF document text
    • http://xn----7sbezcba9a5aggb3j.xn--p1ai/ckfinder/userfiles/files/51321204704.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/161325707b6cf3---nusowabanav.pdfIn PDF document text
    • https://sieuthimaytinhcu.vn/upload/files/dagususabof.pdfIn PDF document text
    • http://vers-ma.de/userfiles/file/81012299797.pdfIn PDF document text
    • http://tatishev.ru/admin/ckfinder/userfiles/files/19343181593.pdfIn PDF document text
    • https://doucetplasticsurgery.com/ckfinder/userfiles/files/95470484155.pdfIn PDF document text
    • http://infrabud.eu/fckpliki/file/sudotusudumogade.pdfIn PDF document text
    • http://ombs.ru/uploads/files/26459367691.pdfIn PDF document text
    • https://cafemocion.com/userfiles/file/kuketunejoxoxujomufepag.pdfIn PDF document text
    • https://makanbanyak.net/contents/files/7520927331.pdfIn PDF document text
    • https://rentcar888.com/uploads/files/202109122219499532.pdfIn PDF document text
    • http://cdn.eagle.mn/uploads/userfiles/files/79409393041.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/1613c859ecf4d6---92234391140.pdfIn PDF document text
    • https://autoroman-service.ro/imagini_ws/gepukit.pdfIn PDF document text
    • http://netflor.pl/upload/File/66568225094.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=largest+country+in+world+in+terms+of+areaPDF 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_off0000f0a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0A2 11076 bytes
SHA-256: 6d55025ce03b1dc75a4ef538d4e6c0588abb03c9046423f5646d521bc54fb6dc
font_01_sfnt_off00010a4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A4B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001225d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1225D 18048 bytes
SHA-256: d62aec1e630445fc6a16f3654949efd1a0b7d844edd1648c36b0d047d4df02eb