Malicious PDF — malware analysis report

Static analysis result for SHA-256 8273f61b323c8f23…

MALICIOUS

PDF

69.5 KB Created: 2021-09-29 08:29:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4502af1d75bef10e6f8f81d4794296a9 SHA-1: 42c268dead10abb17f79e416375339a66d25fc98 SHA-256: 8273f61b323c8f2374345b90a1e7365c2434f7542ed04d6e25c6cc57629cc7e5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The file is a PDF document identified as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs that form a link farm, with several pointing to compromised WordPress sites and disposable hosting. The presence of these links suggests an attempt to direct users to malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://ketchas.ru/uplcv?utm_term=download+video+dari+uc+browser+android
    • http://cerezolorente.com/files/cerezolorente/_repo/file/mudop.pdf
    • https://www.bakkersvlaanderen.be/resources/plugins/ckfinder/userfiles/0/files/zoposadokas.pdf
    • http://centonze-vini.com/userfiles/files/45178682459.pdf
    • http://brixtontaxi.com/survey/userfiles/files/leroromewavenexe.pdf
    • http://slstudio.it/userfiles/files/54140249638.pdf
    • http://learningkey.org/userfiles/fenujidedejubalezubif.pdf
    • http://tamker.hu/userfiles/file/34698808252.pdf
    • https://grandiosieventinuziali.it/filesUploads/file/semibinapozeku.pdf
    • http://ride-on-earth.com/images/blog/file/30026419974.pdf
    • https://www.db-ynox.fr/ckfinder/userfiles/files/suwuxuraginoti.pdf
    • http://mastrodibaglio.it/userfiles/files/gixomalosuxeguf.pdf
    • http://bjerkelunden.org/content/files/userfiles/file///gexulelususodujazelun.pdf
    • http://ayurveda-shiatsu-qigong-nice.com/upload/files/89812348020.pdf
    • https://thehideawayresortpattaya.com/userfiles/files/ruxade.pdf
    • http://iktoktatas.hu/files/file/rabapezanijitazepinu.pdf
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/16144bbf8b2d46---wepopuwutudovan.pdf
    • http://bukharaalpharetta.com/sites/default/files/file/12642178680.pdf
    • http://xn--elementy-zczne-kwb98g.pl/media/file/dojiriso.pdf
    • https://radmangroup-ye.com/rgfiles/file/moxidenepoganewuzesa.pdf
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135ce46583a0---72252073631.pdf
    • http://ytovietnam.net/ckfinder/userfiles/files/51190679345.pdf
    • http://omnoiptv.com/outscapes/admin/ckeditor/uploads/ck/files/61839273705.pdf
    • http://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/548f5e137739b82a815f1ad41ca08de0/jiramuwekesigoxuw.pdf
    • http://bukharajohnscreek.com/sites/default/files/file/57270351490.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_off0000b28a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB28A 16792 bytes
font_01_sfnt_off0000caa1.bin
177026f4f95dcb5fdeeb7800fad772b42b0a619bf5f6ff6e371f7d28eda55ed4
pdf-font-stream PDF embedded font (sfnt) at offset 0xCAA1 10656 bytes
font_02_sfnt_off0000e323.bin
06d787793d8fc7c7ef378f605ffbb86cc3c8bbe4cb68b92a398da354b571a7e3
pdf-font-stream PDF embedded font (sfnt) at offset 0xE323 14636 bytes