Malicious PDF — malware analysis report

Static analysis result for SHA-256 421ef53ac0e72812…

MALICIOUS

PDF

94.8 KB Created: 2021-07-23 00:11:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 16c416624571b2f3736868ba10266fd9 SHA-1: 2b904517d6e667578d64ac482d86bd1951b3d98b SHA-256: 421ef53ac0e72812143a648301e1c970f0853951c06d8b1b7d9feab20bd9193c
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF was flagged by multiple heuristics and a machine learning classifier as malicious, specifically as a phishing or trojan delivery mechanism. The document body, though heavily obfuscated, combined with the heuristics for 'Fake invoice / payment lure' and 'Callback phishing phone lure', suggests a social engineering attempt to trick the user into interacting with malicious links. The numerous embedded URLs pointing to compromised CMS uploads and disposable hosting further support this. The primary attack vector appears to be directing users to download further malicious content via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 8

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) or Microsoft license-boilerplate documents that carry no urgency or charge/dispute escalation.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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://christembassyromford.org/wp-content/plugins/super-forms/uploads/php/files/ca8207bd6af5b51b72d65b4b812a373d/42940762422.pdf In PDF document text
    • http://fusen-es.info/yamituki-n/uploads/files/buwawobosasozowi.pdfIn PDF document text
    • https://geo-decouverte.kenamedia.ch/ck/ckfinder/userfiles/files/kululovosiwebuselotifazog.pdfIn PDF document text
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/1609b3b00614a5---14556649454.pdfIn PDF document text
    • http://snap-drone.com/userfiles/file/51656339888.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/6ct1um7nb8c4psll5dra8o3t46/soworewunesonujexuje.pdfIn PDF document text
    • http://www.orhancoskun.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e6876751757---betapuga.pdfIn PDF document text
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/160911bd8470af---zikafaki.pdfIn PDF document text
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/160da00761b7bf---nogasajote.pdfIn PDF document text
    • http://marinda.ru/pics/images/file/2259916508.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/16078648fdc409---dezubit.pdfIn PDF document text
    • http://alconburyreunion.com/clients/36523/File/63808519421.pdfIn PDF document text
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086a30ea3999---toxobeselikivazufuvebe.pdfIn PDF document text
    • https://vallejardin.com/wp-content/plugins/super-forms/uploads/php/files/6a9c7e9f99e955e19281b1b5bacd7fb0/67221770941.pdfIn PDF document text
    • http://automozg.by/upload/editor/files/jomiforumolelirakevujem.pdfIn PDF document text
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc7331922c2---linirux.pdfIn PDF document text
    • http://mmckno2010.zkosuchdol.info/files/vinige.pdfIn PDF document text
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16085130650dbb---22850508619.pdfIn PDF document text
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/9micl9o5jqigjr5gs29m3fo5c0/21825716487.pdfIn PDF document text
    • https://diversified-nj.com/wp-content/plugins/super-forms/uploads/php/files/ca9bd5059fd5a838c712319b8bd8077e/papekelaludutuxolavu.pdfIn PDF document text
    • http://laptopplus.be/app/webroot/files/userfiles/files/kusokajupumuxoxasavo.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c5c65430a32---82098162491.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=coughing+up+brown+phlegmPDF link annotation
    • 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_off00011108.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11108 10628 bytes
SHA-256: 67a6bea9aa4270cdef61878a957f9fe05f05f0ee21051bc55440f69caaea882a
font_01_sfnt_off000128e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128E5 17092 bytes
SHA-256: 57a097c01fec1ad5039209bd1bae385d91894f763aa26a5c4fd1bf99f209f10c
font_02_sfnt_off00015566.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15566 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1