Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc83855aabdb035f…

MALICIOUS

PDF

77.9 KB Created: 2021-09-08 20:52:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 53ea00f489edab2ebec9225e77300a15 SHA-1: 6128a44d8efc639171ec5ade4649e024835b54b5 SHA-256: bc83855aabdb035f48b37c6c1f1e47f9af3aa56bd99720ac4aa9fa74d85fdc07
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a malicious document, potentially leveraging embedded JavaScript for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://allytemp.ru/uplcv?utm_term=characteristics+of+an+effective+teacher+education+programme+pdf PDF link annotation
    • https://qamarapps.com/wp-content/plugins/formcraft/file-upload/server/content/files/161378ec469be3---dugomazugoxapawelivise.pdfIn PDF document text
    • https://inprovitparaguay.com/ckfinder/userfiles/files/44232548087.pdfIn PDF document text
    • https://hssanesteban.cl/files/masulufuzupaxelekelipek.pdfIn PDF document text
    • https://campermagazine.tv/public/file/zuguzufufigabanewibe.pdfIn PDF document text
    • https://churchosonline.com/wp-content/plugins/super-forms/uploads/php/files/7fee07733e7b02dbbaf28d634a16cfe9/pivovonipebofupux.pdfIn PDF document text
    • https://vpmemorial.net/images/file/4078432758.pdfIn PDF document text
    • http://anabakorea.jp/userfiles/file/98423532215.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/1613043f5889ff---65999999580.pdfIn PDF document text
    • http://altiro.nl/home/tjerk/file/gevures.pdfIn PDF document text
    • http://clickvay.com/upload/files/wolerutumidifovabepef.pdfIn PDF document text
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161354b51ee9c3---robasijidibod.pdfIn PDF document text
    • http://darstin.com/userfiles/files/65317550253.pdfIn PDF document text
    • http://ain.proximeo.com/ckfinder/userfiles/files/88774138562.pdfIn PDF document text
    • http://thechitay.com/uploads/userfiles/file/tixelutinaganejuliwuvim.pdfIn PDF document text
    • http://22vek-omsk.ru/fck_editor_files/files/xagegakejad.pdfIn PDF document text
    • https://grandhotelushba.com/userfiles/file/lejuvetu.pdfIn PDF document text
    • http://bestpokeya.com/uploads/files/kokuletuwakunevid.pdfIn PDF document text
    • http://carbontuning.ru/file/netazisowewaku.pdfIn PDF document text
    • http://darslaska.org/ckfinder/userfiles/files/25450616887.pdfIn PDF document text
    • http://sp3siemianowice.pl/userFiles/files/menalened.pdfIn PDF document text
    • 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_off0000ca85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA85 11220 bytes
SHA-256: 455e858a6019037a275b43b1f4190c92c6e6981836af2f46d548553c0836b3b1
font_01_sfnt_off0000e47a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE47A 17344 bytes
SHA-256: 1b24a546515d9b4938565600a4eec9944925bcbde657c029eaffffb180670663
font_02_sfnt_off000111b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111B9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1