Malicious PDF — malware analysis report

Static analysis result for SHA-256 935d5078fc23b231…

MALICIOUS

PDF

70.7 KB Created: 2021-09-27 02:49:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 25e48f56786262b95ef40c948b240d04 SHA-1: 756d057e61c3bf65b0218745b0059f340ac1537e SHA-256: 935d5078fc23b23120c9436d64085c3fe2149205e63ecbc4ca7a71c80ec73023
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. ClamAV detected this file as Pdf.Phishing.Trojan, and ML classifiers also flagged it as malicious. The presence of multiple external URIs and compromised CMS upload links indicates a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://infrive.ru/uplcv?utm_term=sonic+mania+apk+download+android PDF link annotation
    • https://socialacademy.gr/wp-content/plugins/super-forms/uploads/php/files/46bb9b27fcdf8df34143cf3f19d76b8f/45877471084.pdfIn PDF document text
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fbe17d8b56---38570674609.pdfIn PDF document text
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614162c448ff0---repamunasumusiju.pdfIn PDF document text
    • https://fond.ru/userfiles/file/fiveterusaxoxatapoge.pdfIn PDF document text
    • http://fcvperu.org/data/fcvperu/userfiles/file/70663527142.pdfIn PDF document text
    • http://bbhshipyard.com/userfiles/file/sogigofawidimabovigi.pdfIn PDF document text
    • http://patanamachine.com/imgUpload/files/daluwirekirepaforibamegi.pdfIn PDF document text
    • http://se-ty.com/uploads/userfiles/file/81458154948.pdfIn PDF document text
    • http://davobio.com/upload/files/72549187872.pdfIn PDF document text
    • https://812423.situshoki1.com/contents/files/9902633370.pdfIn PDF document text
    • http://karat-dobremiasto.pl/userfiles/file/kesavafulipi.pdfIn PDF document text
    • http://bronnicy.inhome360.ru/admin/ckfinder/userfiles/files/pozawizurekojututaneg.pdfIn PDF document text
    • http://zamgph.com/uploads/file/22021521763.pdfIn PDF document text
    • http://xn----gtbercbfedtm3b.xn--p1ai/admin/ckfinder/userfiles/files/43753221124.pdfIn PDF document text
    • https://prestinieurope.ch/userfiles/files/61253849276.pdfIn PDF document text
    • https://systematix.pl/userfiles/file/vebumoriten.pdfIn PDF document text
    • https://tedesco.pl/userfiles/file/rosaxajujakomiriz.pdfIn PDF document text
    • https://printjet.pl/pliki_user/File/fibonuxizev.pdfIn PDF document text
    • http://grafitym.kz/files/file/jaregipulapuje.pdfIn PDF document text
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/869915dd5f0a3cbf16f0abad7fe4f559/sukik.pdfIn PDF document text
    • http://silverk.ru/img/lib/file/26734374033.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_off0000b032.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB032 10528 bytes
SHA-256: 6d50f67a8296836b5fe7c1e1986f60cc485adc5428537379162f1683002ab215
font_01_sfnt_off0000c82b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC82B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e03d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE03D 17484 bytes
SHA-256: 2f18ff9b20f144f9d979052728ea5ca21bfdc748460574d62e55a61ff1136f9e