Malicious PDF — malware analysis report

Static analysis result for SHA-256 fff083e983e97bf8…

MALICIOUS

PDF

79.4 KB Created: 2021-09-08 14:28:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 9236890d4f699b7324ecdb79ce7ffc22 SHA-1: 2a91d9c4273f43e3f0eb3bf97d908f2a45226b95 SHA-256: fff083e983e97bf85ba6d2fe53c7106f4ab61657c0fd2ea3eb15b6459db22e0d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing a link farm that points to multiple compromised websites, likely intended to host malicious content or phishing pages. The ML classifier and ClamAV detection strongly indicate malicious intent, with the PDF likely serving as a lure to redirect users to these compromised domains. No scripts were extracted, but the PDF structure itself facilitates the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

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://sieuthimaytinhcu.vn/upload/files/66950414522.pdf In PDF document text
    • http://avanti.pl/userfiles/file/ralumogosaziduta.pdfIn PDF document text
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/16133ab6cd9eb2---23942289230.pdfIn PDF document text
    • http://happinessgown.com/upload/users/files/fonetuzekofenosipawa.pdfIn PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613222f593763---26039262279.pdfIn PDF document text
    • https://bibliotheque-des-arts.ch/ckfinder/userfiles/files/tipefukorelunu.pdfIn PDF document text
    • http://dvarenda.ru/upload/file/nemikifujebi.pdfIn PDF document text
    • http://www.emporiocaritaspisa.it/wordpress/wp-content/plugins/formcraft/file-upload/server/content/files/1612f869b529c7---83755157394.pdfIn PDF document text
    • http://8njl.com/userfiles/files/gatifeti.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/1613596da3a369---477315350.pdfIn PDF document text
    • https://valenciamaids.com/userfiles/files/funaxisijas.pdfIn PDF document text
    • https://www.syria-report.com/sites/all/libraries/ckfinder/userfiles/files/fejugunodazigotosexo.pdfIn PDF document text
    • http://ck-kutnahora.cz/gais/image/file/jajimebilasewad.pdfIn PDF document text
    • https://aymexco.eu/ckfinder/userfiles/files/wokadifuwof.pdfIn PDF document text
    • http://moyamoya.center/images/hand_uploaded/files/sotevopufutevewojuwes.pdfIn PDF document text
    • https://yoimart.com/upload/file/20210903234848.pdfIn PDF document text
    • http://tweedehandswikkelaar.nl/app/webroot/files/userfiles/files/nogoseduden.pdfIn PDF document text
    • https://cleartunemonitors.com/ckfinder/userfiles/files/23152415280.pdfIn PDF document text
    • http://marktoby.com/akram/know_news/admin/userfiles/file/47020308321.pdfIn PDF document text
    • http://lycee-elm.org/userfiles/file/37948251098.pdfIn PDF document text
    • http://kameleonhastanc.hu/files/file/jadulilixupowexig.pdfIn PDF document text
    • http://hanlacsclub.com/ckupload/files/17775358454.pdfIn PDF document text
    • https://dallaslandscapedesign.com/media/files/mazakevigiketexeloxaweb.pdfIn PDF document text
    • http://aivieksteslaivas.lv/userfiles/file/sagexewataxibatefijaxan.pdfIn PDF document text
    • http://stickerbarcode.com/file_media/file_image/file/57847327259.pdfIn PDF document text
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/69e004a669f454db187f298bfe628598/23013808815.pdfIn PDF document text
    • https://renault-service.com/userfiles/3457167563.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=caperucita+roja+hermanos+grimm+editorial+panini+pdfPDF 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_off0000cda9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDA9 18788 bytes
SHA-256: 9794c1d3efd0ffcb89fd484c238f1bdc3c665b20285ca1e43fc1f539b17491fc
font_01_sfnt_off0000fdb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDB3 11328 bytes
SHA-256: df0f7d4d757d74f01b7e131c27f44586fce141f5654d939b7832755c133004ce
font_02_sfnt_off000117ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117EE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1