Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4fdf6e817f575be…

MALICIOUS

PDF

80.9 KB Created: 2021-09-10 02:15:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 8a08ac15f518abae6309d94236f2b8b5 SHA-1: 0967b7aae25b93c86ef85cbf8d6cb2a8521cf034 SHA-256: d4fdf6e817f575be79663b0c3a794db971bb95e704846662da46b9b895345309
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous links, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of external URIs and link farm heuristics strongly indicates an attempt to lure users to external resources, likely for further exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://rippa.pt/files/file/rizilutezer.pdf In PDF document text
    • https://proektasis.gr/admin/spaw2/uploads/files/73896609411.pdfIn PDF document text
    • http://adamslakeband.org/userfiles/file/76781336321.pdfIn PDF document text
    • http://xy-interior.com/uploads/files/202109050802408695.pdfIn PDF document text
    • https://ferado.vn/userfiles/file/42302469327.pdfIn PDF document text
    • https://holcom-solar.com/webroot/img/files/36975932925.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132a6d6af974---62460781322.pdfIn PDF document text
    • http://rurisnet.org/images/file/nagururiromuxe.pdfIn PDF document text
    • http://cochemical.com/upload/files/97757561617.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/94vhfga5iq8lad5bfq9d2fsiq5/daxupokofotobakat.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135b0afae30e---ruvin.pdfIn PDF document text
    • http://ahkjt.com/upfile/file/rogavazeximuni.pdfIn PDF document text
    • http://www.anaja-inter.org/public/file/34715996426.pdfIn PDF document text
    • http://gsxr.hu/userfiles/file/jesew.pdfIn PDF document text
    • https://www.vpn-solutions.com.pe/ckfinder/userfiles/files/riterubelidatipolepuf.pdfIn PDF document text
    • https://yantrasearch.com/ckfinder/userfiles/files/texuwadepisumazasal.pdfIn PDF document text
    • https://singhaniabrothersltd.com/ckeditor/ckfinder/userfiles/files/45513331889.pdfIn PDF document text
    • https://jjpremiers.com/files/48745218641.pdfIn PDF document text
    • http://www.prunay-en-yvelines.fr/ckfinder/userfiles/files/bivazel.pdfIn PDF document text
    • http://chongros.com/userData/board/file/bejuwa.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134ef2d0e07d---jojolilexetimoxogoborafe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=legend+of+korra+season+4+onlinePDF 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_off0000d662.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD662 18320 bytes
SHA-256: 9f083a6f68cb5554a9b647f5d6efa1965c4e522a70aa0dc34a5d19ff3c1d402d
font_01_sfnt_off00010658.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10658 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011e6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E6F 10560 bytes
SHA-256: 6ae37a3f8ba47098b003531f838488cb838174441a39cc1f9e5cdb07f0e412dc