Malicious PDF — malware analysis report

Static analysis result for SHA-256 d5f21531daf4de67…

MALICIOUS

PDF

82.5 KB Created: 2021-09-10 15:37:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 718e4a427c59aa98d3b16fd8aec6be8b SHA-1: b388fe2d25b70d7ccc8702898812c7b5fb9cc693 SHA-256: d5f21531daf4de673ffe836bb34889ddd5321fd1b2a7e5026b2895ec4913098c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by ML classifiers and ClamAV as malicious. It contains numerous external links, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users. The PDF structure and embedded URLs indicate a phishing or malware distribution attempt, likely initiated via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://inwebjor.ru/uplcv?utm_term=tropical+rainforest+human+impact PDF link annotation
    • http://burragebrothers.org/demo/jolie/beta/userfiles/files/regigezirutekofokatego.pdfIn PDF document text
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/599de7cdda4723a69d05830a7680f4de/sutagulatijupufijek.pdfIn PDF document text
    • https://nguoixunghekiev.vn/userfiles/file/sutozixameruxivimenise.pdfIn PDF document text
    • http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/161326ebdd9e15---9179303814.pdfIn PDF document text
    • http://ingpiazza.eu/userfiles/files/masuxopol.pdfIn PDF document text
    • http://huyndaicaudien.com/upload/files/22030653609.pdfIn PDF document text
    • https://vieclamlaocai.vn/webroot/img/files/1519896302.pdfIn PDF document text
    • http://studiocariola.com/userfiles/files/72105913870.pdfIn PDF document text
    • https://dgssu.com/upfolder/e/files/20210904151516.pdfIn PDF document text
    • https://www.greenlakecruises.com/ckfinder/userfiles/files/fatufuvepuparujam.pdfIn PDF document text
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/161309175f0f21---zeserafokekozuku.pdfIn PDF document text
    • https://rockyhotelsgroup.com/uploaded/files/16423494545.pdfIn PDF document text
    • http://firstcuwire.com/file_media/file_image/file/71067988804.pdfIn PDF document text
    • https://euroroma-bg.org/files/file/79546406169.pdfIn PDF document text
    • https://dnsbp.com/all4help/fckuserfiles/file/zovojefuwolozot.pdfIn PDF document text
    • http://tlumacz-lipno.pl/pdrzewiecki/files/pijivafoxij.pdfIn PDF document text
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/161373c1dcc1a8---kovug.pdfIn PDF document text
    • http://alacarte-grafik.de/userfiles/file/fezuxuz.pdfIn PDF document text
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/2940cc0141b7f09437365875d3223f57/zogavanaz.pdfIn PDF document text
    • http://novelinternationalschool.com/ckfinder/userfiles/files/bisakivebomofilep.pdfIn PDF document text
    • http://bapassamarinda.id/assets/ckfinder/core/connector/php/uploads/files/50509440983.pdfIn PDF document text
    • http://xn--76-6kca8aqc6c.xn--p1ai/pic/userfile/60898044021.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_off0000dd68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD68 17960 bytes
SHA-256: cb335df8966bba41c792331f26df8793ee79afac04bd4a93c7f14c1837875929
font_01_sfnt_off00010c4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C4D 10808 bytes
SHA-256: 33c62ce3e3366cdca8a69b8cd053b279a02fe547c6247f2100bd554c9d5c8573
font_02_sfnt_off00012502.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12502 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1