Malicious PDF — malware analysis report

Static analysis result for SHA-256 b68f56a2e3caa7ac…

MALICIOUS

PDF

71.2 KB Created: 2021-05-21 04:52:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 33c3c5a37151347cf0be7dc62480f709 SHA-1: 517a3a0db08ffd810329d83ba7babf7e5f6a7980 SHA-256: b68f56a2e3caa7ac8e28b98089128321bffb35111644ddfa83035af06cad3ca1
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as a link farm, with many URLs pointing to compromised WordPress sites. The ML classifier and ClamAV also identified it as malicious, specifically as a phishing trojan. The embedded content, though largely unreadable, contains references to 'wkhtmltopdf' and 'Qt', suggesting it was generated by a tool rather than being a legitimate document. The primary attack pattern involves directing users to potentially malicious external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://amerismithenterprises.com/wp-content/plugins/super-forms/uploads/php/files/20100bd22cd0ab6bb7b10ebd045fcd9f/87956288675.pdf
    • https://discoverapartmentsforrent.com/wp-content/plugins/super-forms/uploads/php/files/fc25b8813251422101bbbb40612bc102/romasilinofemuponi.pdf
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/160a5aec3db1ce---79318468148.pdf
    • https://loskutova.site/wp-content/plugins/super-forms/uploads/php/files/bc67fde9bdc1c036081b7cc9c4e3cb35/loroworonopabi.pdf
    • https://law.com.sg/wp-content/plugins/super-forms/uploads/php/files/12b33d77d5c2a6f68c04d9176fa531d7/jevat.pdf
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/160a1ef1045a08---5684290770.pdf
    • http://lotuscourtpune.com/wp-content/plugins/super-forms/uploads/php/files/g77gnac9tusi13q58a70pn5ot2/liwuwabapirazawopabilo.pdf
    • https://www.infratechgroep.nl/wp-content/plugins/super-forms/uploads/php/files/99c46a8d32a09a8bb3be275508d6b25d/4119995340.pdf
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8d5586ac3---67407217599.pdf
    • https://www.psalighting.com/wp-content/plugins/super-forms/uploads/php/files/f7ce55c2ccb391e5ff5b809c5d2950fa/3414923950.pdf
    • https://amenagementsoleil.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc195d0e31---xotavizoxajexu.pdf
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a567b2ea85f---maxijapanawexabod.pdf
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16087f53e164bb---35977422174.pdf
    • https://cursosgratuitosonline.es/wp-content/plugins/super-forms/uploads/php/files/pl94e6ut82ml13v1o1pkmcm0s1/xadininobebeje.pdf
    • https://hopefor.today/wp-content/plugins/super-forms/uploads/php/files/2c6fb214ce62cf1779c6ab4e3d4d0fe6/susomonaperatekufo.pdf
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160879354e9196---gedop.pdf
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ec901ac912---29709999144.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=elementary+differential+equations+11th+edition+ebook
    • 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://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000da38.bin
c1c43bb0162d9ff913093741a31419b6309213e30e322b4956c130007569ebdf
pdf-font-stream PDF embedded font (sfnt) at offset 0xDA38 5588 bytes
font_01_sfnt_off0000ed13.bin
7d3f53fb8de74bd40b45f46ac87aadb4b4e9e086bd657a12cf7201bc87222418
pdf-font-stream PDF embedded font (sfnt) at offset 0xED13 10132 bytes