Malicious PDF — malware analysis report

Static analysis result for SHA-256 20e8e5a3da29b497…

MALICIOUS

PDF

89.1 KB Created: 2021-09-01 23:13:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f288557b4a5fa20d59744f3418a9b48e SHA-1: fb51d75db6557bbb0aa8b485ef1ec9fa38d7948e SHA-256: 20e8e5a3da29b497bd7848026c9fa6a66f140f219d59aa5807e0962c582bd67b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for malicious PDFs. It also contains a large number of external links, many of which point to disposable hosting or compromised CMS uploads, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution via these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 http://biirbeh.mn/images/content/file/34716385211.pdf
    • http://royalrep.com/userfiles/files/22470626857.pdf
    • https://imahima.xyz/js/ckfinder/userfiles/files/dumumezopodesirubarupu.pdf
    • http://budohurtsa.pl/userfiles/file/zowitutigijavoduleke.pdf
    • https://harrisitalia.it/uploads/file/kawegadezi.pdf
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/083ae558537540a6d902865a8e1c49fe/virizotawemelaranuw.pdf
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/1606e7367db35a---85813449345.pdf
    • http://www2.grupoksl.com.br/js/ckfinder/userfiles/files/89282565585.pdf
    • http://hum-lucknow.org/test/fckeditor/file/bezaranotiwaxo.pdf
    • https://glass-haus.ru/wp-content/plugins/super-forms/uploads/php/files/9fff88bd9d5da59c64cc1720c645ca98/labavazek.pdf
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/ee8c123fc2c9569ed66073d35358e87f/17418194784.pdf
    • https://vicotelecom.vn/static/source/images/file/nijuvuxipatim.pdf
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files//dapojazax.pdf
    • https://earthideasawnings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a01024245f8---6009084579.pdf
    • http://pogologistics.com/ckfinder/userfiles/files/pekomalilovedutovukuromo.pdf
    • http://zgkimsteszew.pl/img/upload/files/soxijuramojokusefopisedok.pdf
    • http://exhibitionchannel.com/upload/petadiketudoxi.pdf
    • https://cwlighting.com/wp-content/plugins/super-forms/uploads/php/files/157eed27034face92e873b7275e74157/dubejeporafek.pdf
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f8b9cb34ce---81686395866.pdf
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/160a27a9da7f7d---76288226087.pdf
    • http://esoftland.com/userfiles/file/fixoxonepufadojomiket.pdf
    • https://telechips.com/ckfinder/userfiles/files/25524507128.pdf
    • http://zaiger.ru/img/file/60982524036.pdf
    • https://www.ediliziaindustriale.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b11104da45b---berinaxiwom.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=closing+time+song+the+office
    • 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_off0000f2f7.bin
648e04d656060c9783b6138736d012789c7b4e44dea39b59c4c7b5494545be41
pdf-font-stream PDF embedded font (sfnt) at offset 0xF2F7 10552 bytes
font_01_sfnt_off00010ad2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10AD2 16792 bytes
font_02_sfnt_off000122e4.bin
4d050517c515f69f0d6e1233164d9e03ec929f281bae8913a9c40f95c6331eca
pdf-font-stream PDF embedded font (sfnt) at offset 0x122E4 19992 bytes