Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c90a17a1df91a8d…

MALICIOUS

PDF

69.1 KB Created: 2021-09-05 12:32:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 46ec080bb848097648145066b0a4e4f7 SHA-1: e23108834ce043bd25fe260e9b5d0961104ed68f SHA-256: 3c90a17a1df91a8d43ac5234ccd9d45131437883556f57ae31c97f7dd03f322d
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites, likely intended to lure users into downloading further malicious content or visiting phishing pages. The presence of multiple compromised CMS upload links indicates a pattern of hosting malicious files on seemingly legitimate but compromised infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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 https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612718c1e51ff---wusopejegimidi.pdf
    • http://www.umadai.com/ckfinder/userfiles/files/tupojotij.pdf
    • http://www.roosprommenschenckelfoundation.nl/ckfinder/files/files/93345759375.pdf
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/160833b2ab3bab---nusidisowatoxemukak.pdf
    • http://sibleyestateplanning.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/26695391918.pdf
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/65422e48cd855d07fafe2e34614162f5/74939181202.pdf
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/e0a688fd39c015bfb4c370669e79b32e/37148032005.pdf
    • https://hondaotohaiphong.vn/upload/files/pudalumamugoketomixeto.pdf
    • http://hasyo.net/files/file/mojunejoxobimubabibuwisup.pdf
    • https://chung-pei.com/userfiles/file/zirowagepuzilofigotijut.pdf
    • http://uss100.com/clients/5/56/562308f4da1da23328cfd9e5c9f3e68f/File/difaduzusaz.pdf
    • http://eotp.info/sites/default/files/fck/file/67416284102.pdf
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/160829a805db00---jevojovuzuli.pdf
    • https://cornerstonelaw.eu/userfiles//file/sowajavimorozuzoposad.pdf
    • http://www.scea.edu.mn/ckfinder/userfiles/files/11362786787.pdf
    • http://otczenacts.com/media/files/33728882003.pdf
    • http://mmckno2010.zkosuchdol.info/files/sodakaso.pdf
    • https://rsun.pro/admin/ckfinder/userfiles/files/49200602625.pdf
    • https://forcechicago.com/wp-content/plugins/super-forms/uploads/php/files/1160d91fd0660dd44713378662cd126b/luxanowazapesusadidel.pdf
    • https://hondamienbac.vn/userfiles/file/piwunojokefixugusotexe.pdf
    • https://viadagio.be/userfiles/file/58985638259.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=satisfaccion+del+cliente+definicion+pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b2fe.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB2FE 16792 bytes
font_01_sfnt_off0000cb15.bin
d70fb42c646a5c185edc6008bc1666ea242a9e6d791356b7922cf31926c58643
pdf-font-stream PDF embedded font (sfnt) at offset 0xCB15 10588 bytes
font_02_sfnt_off0000e357.bin
17d46c99271568e0b1be4e2cd4188742bf1098e0eb83f975b956b529c97493f6
pdf-font-stream PDF embedded font (sfnt) at offset 0xE357 14348 bytes