Malicious PDF — malware analysis report

Static analysis result for SHA-256 81628ffb0d620339…

MALICIOUS

PDF

98.4 KB Created: 2021-06-12 05:51:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 92cf5f4cd1660e5951220b24c3c806c6 SHA-1: 33fe23ef868b87c33f7e4d450d9734b2908a7e30 SHA-256: 81628ffb0d620339e7cac1dd337ba72c9a4203b4f3290c366be6bd987b36ded4
156 Risk Score

Malware Insights

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

This PDF document is classified as malicious by ML and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many hosted on compromised CMS uploads, suggesting a phishing or malware distribution scheme. The document body, though partially obfuscated, appears to be a lure related to a 'vocabulary worksheet answer key', designed to trick users into visiting these malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 6

  • 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.
  • 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://crysiq.ru/uplcv?utm_term=the+gift+of+the+magi+vocabulary+worksheet+answer+key PDF link annotation
    • https://acethamessecurity.co.uk/wp-content/plugins/super-forms/uploads/php/files/dc692cd16a584231b28958af06fd406e/63525474022.pdfIn PDF document text
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/1e391bb190bfb29bd60781caaf3b41d5/vebegowikarumomepuxe.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16090ae0fb847c---josizilobezaruzuse.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/42df0e114ff03df015426ef69ef68479/26466152867.pdfIn PDF document text
    • http://voszveszprem.hu/_user/file/budeligegokutagop.pdfIn PDF document text
    • https://mattweidnerlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5ae227811c---42570962949.pdfIn PDF document text
    • https://stijsr.com/userfiles/file/48333468223.pdfIn PDF document text
    • https://singaporenotarypublic.com/wp-content/plugins/super-forms/uploads/php/files/908591c0a86cd88c86a83692089da7f5/taguredudajapugagulid.pdfIn PDF document text
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1609174e7bf96e---4784867765.pdfIn PDF document text
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa2476ec4eb---pifexurefutiribalo.pdfIn PDF document text
    • https://www.alarisusallc.com/wp-content/plugins/super-forms/uploads/php/files/4733d16273b58f89aec75dba941bd740/sibozufot.pdfIn PDF document text
    • http://www.gcsystem.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160837d6d69055---novumigubarirogim.pdfIn PDF document text
    • http://vytvarnyobchod.cz/UserFiles/File/32695824021.pdfIn PDF document text
    • http://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078df429c51f---4841357737.pdfIn PDF document text
    • https://www.sixteengrams.com/wp-content/plugins/super-forms/uploads/php/files/spjqsgk5qkpp15pl40fnsenkrh/mixarajimaneludopelik.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/1607e00d677b7f---dalaleje.pdfIn PDF document text
    • http://diamondsnspurs.com/clients/12200/File/xibupe.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.opentle.orgIn PDF document text
    • http://www.daltonmaag.com/In 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://scripts.sil.org/OFLIn PDF document text
    • http://www.gnu.org/licenses/gpl.htmlIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011e25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E25 5584 bytes
SHA-256: 0e52483e80f42a9526b39fad71f46b01fe5bda481ea9144c984083eb3b956929
font_01_sfnt_off0001310f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1310F 6148 bytes
SHA-256: 149738eb3e1d0bfb4a5732e89a115965e6f0cf3fc4971c694d3ce3619176544d
font_02_sfnt_off000140ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x140EE 12592 bytes
SHA-256: 4de32eccf5c4783962dec935ec26f1400d6c40d88fc35b5ae689a274767085a9
font_03_sfnt_off00016b5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16B5D 4324 bytes
SHA-256: cd94ef65598b1866d0653cdd88243d989fd81359c0e770c2d3a4858f1c2f6d34

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