Malicious PDF — malware analysis report

Static analysis result for SHA-256 9f0282449ed79c58…

MALICIOUS

PDF

77.4 KB Created: 2021-09-16 23:20:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 4c5f66614a13d1b7f45a43bc78e8a63d SHA-1: bfdbc8cc3aa74ea92ff50dfd19886c7a7ecdb145 SHA-256: 9f0282449ed79c5833739b133ed06c73c254f21b72a5612e249b7622239da010
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate the presence of a link farm pointing to compromised WordPress upload storage, suggesting a phishing or malware distribution attempt. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/161414dd1bef79---tegefojedojul.pdf In PDF document text
    • http://www.kotolantopeni.cz/files/82283310478.pdfIn PDF document text
    • http://abwmercury.com/uploads/files/63431059940.pdfIn PDF document text
    • http://marasintl.com/public/ckfinderuploads/files/loxebomagenebo.pdfIn PDF document text
    • https://conexusinternational.com/ckfinder/userfiles/file/zopijuvud.pdfIn PDF document text
    • https://aldaserwis.pl/ckfinder/userfiles/files/7688094497.pdfIn PDF document text
    • https://samsunyapi.com/userfiles/files/kegurijogonefokanoxarude.pdfIn PDF document text
    • http://laxycoffee.com/upload/files/tetixopoxanar.pdfIn PDF document text
    • https://www.sahabatkeluargahomecare.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613387ca0b698---99314785190.pdfIn PDF document text
    • http://duythuc-bearing.vn/uploads/userfiles/file/pevivajenogitavogoxi.pdfIn PDF document text
    • https://stw-nowogard.pl/download/file/jifinigetukazu.pdfIn PDF document text
    • http://doo-san.com/userfiles/file/20210905001316.pdfIn PDF document text
    • http://csc0512.com/userfiles/file/20210914021240_pawpbt.pdfIn PDF document text
    • http://www.kickcommerce.com/userfiles/file/timovuponozutabejomemapa.pdfIn PDF document text
    • https://dancleland.com/img/upload/file/mekuzatosur.pdfIn PDF document text
    • http://szpitalstrzelin.pl/userfiles/files/lafinukotajiduzeman.pdfIn PDF document text
    • https://edukiya.com/wp-content/plugins/super-forms/uploads/php/files/117ed1bdcaea5c1ae76769158abded20/99815340512.pdfIn PDF document text
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/nbv2j07bjqfdu97op3uuoqn9cd/josaxetiv.pdfIn PDF document text
    • http://gocreate.termall.pl/upload/fck/file/5901874772.pdfIn PDF document text
    • https://autotoner123.com/home/autotone/public_html/ckeditortest_WORKING/ckfinder/userfiles/files/87944072012.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=android+vs+ios+market+share+australiaPDF 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_off0000cbfd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBFD 10752 bytes
SHA-256: 22d456856d106748638f73e972008a85ca4c4a51a91239bcda84d1250566b96d
font_01_sfnt_off0000e48b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE48B 16996 bytes
SHA-256: 608f3f4e34ba5fbb53f31b4508c2fb288eca82a2b88876eeae8a75ceec3d32bf
font_02_sfnt_off00011079.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11079 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1