Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf51e8f6448b099d…

MALICIOUS

PDF

79.0 KB Created: 2021-09-08 17:07:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: c0d4a2d399ee35da6bca70b76bb9247b SHA-1: 6afb316c844a21e984fcc4d4d0d7da41a42efb56 SHA-256: bf51e8f6448b099d45f08b5e6764bed6df8dc9477f6dcbd9ce799840f941ddb8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised WordPress sites. The presence of embedded URLs and the nature of the heuristics suggest the document is designed to lure users to phishing or malware distribution sites.

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://irlanc.ru/uplcv?utm_term=nmap+tutorial+for+beginners+pdf PDF link annotation
    • http://snsi.jp/image/news_file/49723643559.pdfIn PDF document text
    • http://leinerpakgelatine.com/survey/userfiles/files/modadiwovebepopaben.pdfIn PDF document text
    • https://www.parquesanalbertohurtado.cl/ckfinder/userfiles/files/70433202387.pdfIn PDF document text
    • https://stormester.no/files/file/37022734151.pdfIn PDF document text
    • https://geneolock.com/ckfinder/userfiles/files/lazelevisavepurojerek.pdfIn PDF document text
    • http://gdgom.com/upload/file/210903001200436674czyzxt14c4zh.pdfIn PDF document text
    • https://108pizza.pl/uploads/userfiles/files/83086691734.pdfIn PDF document text
    • http://mpu-beratung-brendle.de/userfiles/file/kufekazavenipuvuzadademez.pdfIn PDF document text
    • https://huanghecables.com/d/files/22098783620.pdfIn PDF document text
    • http://kondicionery-elektrostal.ru/upload_picture/file/67879034733.pdfIn PDF document text
    • http://kosmonautika.ee/ckfinder/userfiles/files/duxelude.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/161383b1279b46---97837533800.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135ba9906ad3---62746975746.pdfIn PDF document text
    • http://ros-audit.com/i/up/file/bakukimozote.pdfIn PDF document text
    • https://sarna-zapiekanki.pl/ckfinder/userfiles/files/71686508348.pdfIn PDF document text
    • http://share-world.tw/userfiles/file/51744134114.pdfIn PDF document text
    • http://impressivetravelvietnam.com/upload/files/kifodewagatinimiwaxoguti.pdfIn PDF document text
    • http://gazdalkodjokosan.hu/img/userfiles/file/zajowerotudidunigerijasux.pdfIn PDF document text
    • https://pragatitic.org/ckfinder/userfiles/files/55955953463.pdfIn PDF document text
    • http://vladjurnalist.ru/archive/file/77072453036.pdfIn PDF document text
    • http://hotdeals24x7.com/ci/userfiles/files/moxovijux.pdfIn PDF document text
    • http://furniture83.com/upload/files/mozolupagesubesejinazazes.pdfIn PDF document text
    • http://manpukuorder.com/uploads/files/letimivenuwuvi.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135c3d797f35---11497526663.pdfIn PDF document text
    • 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://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_off0000d472.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD472 11056 bytes
SHA-256: 5c91adbe6bd029159a9ae8f28c4c985e052b59726360edbdf331e17c99363c5a
font_01_sfnt_off0000edb2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDB2 17384 bytes
SHA-256: 98ffde5a57c8a31af99d78ca4d281e0287cb2d851b4905f39c35800819abd62c
font_02_sfnt_off00011aef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AEF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1