Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fd90fac1f1b263f…

MALICIOUS

PDF

83.3 KB Created: 2021-08-17 10:09:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6bb5d27afb43e63035d072f995c57ab1 SHA-1: 685017a474f26e091e6b99ce09e6718ec3b8973e SHA-256: 4fd90fac1f1b263fd1f635b354dbcb70e858469d783fbc4c517c02b5638185ca
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to compromised CMS uploads and disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the primary attack vector appears to be the exploitation of user trust through deceptive links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://nomylo.ru/uplcv?utm_term=is+there+a+free+reverse+landline+phone+lookup+service
    • https://www.corridar.com/wp-content/plugins/super-forms/uploads/php/files/v7ejh9psbt6u0cha2ml93f2h9q/38234651167.pdf
    • https://festivalecolo.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160cbcd3c1942f---86412738026.pdf
    • http://jatyn.cn/upfiles/202105/file/1621481914.pdf
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a52938d800---nonumo.pdf
    • http://pc75.net/upfiles/file/1621630737.pdf
    • https://fmpride.com/wp-content/plugins/super-forms/uploads/php/files/808b152064f13d457e5f217763844272/55647550323.pdf
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609b8efa359d8---89730820623.pdf
    • http://yorktownhs1987.com/clients/57482/File/77092428837.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a99f847b78e---befepupizutaxawiduj.pdf
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/16077fa0040e31---98382578708.pdf
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f57968cf97---1776700070.pdf
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160867755596b5---62106703155.pdf
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608bae90969b7---topimuvuposufir.pdf
    • http://timatey.kz/wp-content/plugins/super-forms/uploads/php/files/jjohj0hhhm8fvfall2tc44lbs3/muwawajuwurumorurotu.pdf
    • http://lisaarkinlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/dovowu.pdf
    • http://drironcat.com/images/file/wetivojunefiwuwovopurakox.pdf
    • http://www.orhancoskun.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e0b92b4b077---91936440354.pdf
    • https://flycam.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1608069e7aaae2---5775306364.pdf
    • https://www.brightfieldbusinesshub.co.uk/wp-content/plugins/super-forms/uploads/php/files/aljdihrojorfsv8p6j9ed4j8va/degebuzimujajid.pdf
    • http://mediaworld.pro/ckfinder/userfiles/files/guladusisobiwunukovovum.pdf
    • http://salukool.ee/upload/userfiles/file/mobuwedexakivezer.pdf
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/160b1eb28e128f---83634578823.pdf
    • https://dubaimotorcycletours.com/uploaded_images/files/31683469405.pdf
    • http://immobilieninvestors.de/userfiles/file/96024794115.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_off0000e157.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE157 16792 bytes
font_01_sfnt_off0000f969.bin
6ed5a05d5fd2985157afc97b1628e0658d147724567e7b49fd3d3edb42f42f9a
pdf-font-stream PDF embedded font (sfnt) at offset 0xF969 17136 bytes
font_02_sfnt_off0001262a.bin
b946ef85fd85c94e4c7507f048193a7e3c4b9380a81893cdecaf26dda1e55080
pdf-font-stream PDF embedded font (sfnt) at offset 0x1262A 10928 bytes