Malicious PDF — malware analysis report

Static analysis result for SHA-256 20a7f8a4fa69d7f3…

MALICIOUS

PDF

138.7 KB Created: 2021-07-05 02:01:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fd4e3a08adf2dc56288c244dfbeef580 SHA-1: d3c131efc0fd1653f6c55d7230ac98b828827f5b SHA-256: 20a7f8a4fa69d7f396c26bc008847183681ab29c76940dfb5ba56aaa163e5b85
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which point to compromised WordPress upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded JavaScript likely facilitates the redirection to these malicious sites, which are presented as a link farm to obscure the true destination and evade basic detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9775

Heuristics 7

  • 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.
  • 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://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/16076199b61e1b---vubolodozutu.pdf
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b6b559934f8---99336640901.pdf
    • https://cosalesrep.com/wp-content/plugins/super-forms/uploads/php/files/2d0fe913046f6c817ee12fa0e0e760ea/xuxibaziwut.pdf
    • http://dhf-china.com/d/files/95132443935.pdf
    • http://kennyre.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608231e34a785---82684357205.pdf
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1608663eab78f0---80120060712.pdf
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b249bc063df---wopexu.pdf
    • http://phuwangnam.com/user_file/file/tagelajoraladeja.pdf
    • http://chromatographvials.com/d/files/59532882992.pdf
    • http://jocoseatee.com/userfiles/files/53873018767.pdf
    • https://jfefood.com/wp-content/plugins/super-forms/uploads/php/files/1b3bf63a16d91ffda43d83517c494d39/dujomilosakosebebufofexiw.pdf
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a44b1e2b73---54394183625.pdf
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/15f315504a25d0fecc571c00ad74b694/zozugi.pdf
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba0559ce84d---87777639743.pdf
    • http://eschool365.in/js/admin/uploadfiles/file/xekotebezodalu.pdf
    • https://signika.pl/Upload/file/52874228725.pdf
    • http://akinmedical.com/uploads/file/bapubovu.pdf
    • http://terralindahigh1981.com/clients/866868/File/molazuxebiripizapojusobe.pdf
    • http://www.communityheroesproject.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609820ccbbfa5---vazezurez.pdf
    • https://tecnicadovolante.com/images/file/6779350168.pdf
    • http://videofilm-tv.ru/content/File/31343698205.pdf
    • https://alkalacarservice.com/public_html/userfiles/file/80054921131.pdf
    • https://deitratech.com/userfiles/file/21961256861.pdf
    • https://pensiuneavlasin.ro/wp-content/plugins/super-forms/uploads/php/files/tcpho0e79f0qdk93iltsu01dpd/33772687391.pdf
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/vfuukfvn5o6oqe868eovt7194k/24276083927.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=bayesian+linear+regression+in+machine+learning
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f55a.bin
2c36c004f393c45d9eb3193b77092aa0b6ea6339b8ca79082313bec1cb63a2d2
pdf-font-stream PDF embedded font (sfnt) at offset 0xF55A 10748 bytes
font_01_sfnt_off00010de7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10DE7 16792 bytes
font_02_sfnt_off000125f9.bin
bb075c271e15179ecc44c12862c9fde445c1f234cc332474dbc6500635fe0ea3
pdf-font-stream PDF embedded font (sfnt) at offset 0x125F9 18164 bytes
font_03_sfnt_off000155e8.bin
976b20e591578451b2e2db64884eae7e5cdd30afdd9f762f70bd102fa8137e63
pdf-font-stream PDF embedded font (sfnt) at offset 0x155E8 80176 bytes