Malicious PDF — malware analysis report

Static analysis result for SHA-256 13376c58e223ce2b…

MALICIOUS

PDF

88.9 KB Created: 2021-09-03 17:48:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 9fec5f4a972233f13054ffd65d973957 SHA-1: b8a56055f88e816a2e3417be9cc46b86dd962ca2 SHA-256: 13376c58e223ce2b442822b5373496cb1718435fd03b6c9e682777b3e516b463
164 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to compromised WordPress upload directories, suggesting a link farm designed to redirect users to malicious content. The presence of a 'download button' heuristic further supports a lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://grand-forge.ru/wp-content/plugins/super-forms/uploads/php/files/211c1830e2a109b4cf85128572e8c090/11687270873.pdf In PDF document text
    • http://shopgraeagle.com/ckeditor/uploads/files/50382676338.pdfIn PDF document text
    • http://srividyaastrology.com/userfiles/file/6157145929.pdfIn PDF document text
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/278eb0a97ea5d77d7739538be844947b/bewigozuzodapakififija.pdfIn PDF document text
    • https://www.cr-sdc.org/wp-content/plugins/super-forms/uploads/php/files/cf1c7430f8977428d47ec994539ffde1/70299608568.pdfIn PDF document text
    • http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/4b85b4f03786198815e4e3afa7f89cc9/xopavib.pdfIn PDF document text
    • http://msnladyboy.com/ckfinder/userfiles/files/virax.pdfIn PDF document text
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/585d4a74f1366220922abda9e6e17e95/80055810073.pdfIn PDF document text
    • http://asbu.net/uploads/FCK_files/file/85721293899.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c888d9bd218---laxoxawaguxonot.pdfIn PDF document text
    • https://actioncoach.com.my/wp-content/plugins/formcraft/file-upload/server/content/files/16089430418882---54294462168.pdfIn PDF document text
    • http://beckydavidsonhomes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e486686d8d---5276580400.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/d5ea523e16311907dd7c5587217a8d34/lixitapimakibuje.pdfIn PDF document text
    • https://oncallanatomist.org/ckfinder/userfiles/files/33302259763.pdfIn PDF document text
    • https://daluxerealty.com/wp-content/plugins/super-forms/uploads/php/files/iorp15g57nl6icr4johl6ve9l7/jufekuvebikituk.pdfIn PDF document text
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/39415284984ef6f210e5034b3fa86981/57937788302.pdfIn PDF document text
    • http://lotuscourtpune.com/wp-content/plugins/super-forms/uploads/php/files/b7defc4e7779acff743fd10c1ff8be3e/58272051776.pdfIn PDF document text
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d8108926c50---93351440315.pdfIn PDF document text
    • http://massageindex.nl/images/uploads/32245436067.pdfIn PDF document text
    • https://unitytradefze.com/ckfinder/userfiles/files/wesobiwezipaso.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aaff11a8226---41084308433.pdfIn PDF document text
    • http://www.asejnrtigers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7b150632c---vosaworulegenavadazaxo.pdfIn PDF document text
    • http://jar-ted.pl/file/xivinuboxovi.pdfIn PDF document text
    • http://www.danvillern.com/wp-content/plugins/super-forms/uploads/php/files/9gu8rod4h2dkboou4bf3aome67/juzow.pdfIn PDF document text
    • http://mnarch.it/userfiles/files/ligoroparadamo.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d6a74cba4a---xomozixifaj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=penguin+readers+level+2+pdf+downloadPDF 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_off0000f42b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF42B 10948 bytes
SHA-256: c1a42b2ddc9de299c029886ce87b224b268da80e19ee400b94b4e0b8dfeaec36
font_01_sfnt_off00010d8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D8F 18596 bytes
SHA-256: 888195b7471c3ac85721225e225c6521efd116c94ebd2ca86f286c1b2e3776ef
font_02_sfnt_off00013db5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13DB5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1