Malicious PDF — malware analysis report

Static analysis result for SHA-256 c691e6954d7268b5…

MALICIOUS

PDF

81.0 KB Created: 2021-09-22 10:49:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fe724dc3c941dc0771d97c5fc39f7ea5 SHA-1: 8f11530814f8fced29fd6acfeb157a5a910ed2b6 SHA-256: c691e6954d7268b58e85648480d200e41408a62f3e679ee5bea8893eeba0649c
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm. Several heuristics indicate that the PDF contains numerous links pointing to external websites, with a notable number hosted on compromised CMS upload directories. The primary attack pattern involves luring users to click on these links, which are likely designed for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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 http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16138fc43cf8ff---gutep.pdf
    • http://chonburi33.com/userfiles/file/gukigowos.pdf
    • https://cr2tek.com/userfiles/Proj_Name/files/lirozop.pdf
    • https://tavcam.com/upload/ckfinder/files/18229067362.pdf
    • http://abcbyspu.net/ckfinder/images_store/files/poralevositoduzaperuwa.pdf
    • http://99hospitalitygroup.com/ckfinder/userfiles/files/xifivusikovorumiwalenewok.pdf
    • http://piotrkowska77.pl/zdjeciafile/59435063842.pdf
    • https://livres-arts.com/ckfinder/userfiles/files/75505792104.pdf
    • http://crystalnymph.by/wp-content/plugins/super-forms/uploads/php/files/61f99b4877659361b7387237003d0d31/tulavowokewigojefezexax.pdf
    • https://egyptsuntours.com/userfiles/files/dudiforeritumezutizu.pdf
    • http://nawarashop.com/phya/ckfinder/userfiles/files/jopezirolebakemonume.pdf
    • http://juha.be/_files/file/piwemufu.pdf
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ba95ec3d0b---9255910879.pdf
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/kqm18gcqor0ffokbo4an12r6k6/90524313021.pdf
    • http://brukikostka.pl/uploads/page/file/wimidupix.pdf
    • http://monteconsultants.com/image/upload/File/2165945794.pdf
    • http://sitoad.com/bbqjoekey/files/202109201708456148.pdf
    • http://meadescafe.com/userfiles/file/dupigezivetubag.pdf
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/16148b29762fd2---23071766873.pdf
    • http://yishiweb.com/upfiles/files/20210916_144303.pdf
    • http://holland-ex.com/images/blog/file/ladev.pdf
    • http://sibinetweek.ru/userfiles/file/futononokunuzo.pdf
    • http://upnbkk.com/file_media/file_image/file/46017203586.pdf
    • http://chandravanshi.com/userfiles/file/gujusodovajulezubirufixi.pdf
    • http://sbnjl.com/userfiles/files/josevegofepelebi.pdf
    • http://motivationandmomentum.net/ci/userfiles/files/10739028547.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=harry+potter+and+the+philosopher%27s+stone+movie+free
    • 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_off0000d6c8.bin
f22ffc1ac7aa93db84be88a89e60bbbb3124e984a6173403da18e0ba5fb35b92
pdf-font-stream PDF embedded font (sfnt) at offset 0xD6C8 10968 bytes
font_01_sfnt_off0000f004.bin
423f25707c7ad48c059a23b980f62ee7111c6e76bcf36983ac80db7cca8c4b99
pdf-font-stream PDF embedded font (sfnt) at offset 0xF004 17644 bytes
font_02_sfnt_off00011e08.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11E08 16792 bytes