Malicious PDF — malware analysis report

Static analysis result for SHA-256 c662dc76b1f52f06…

MALICIOUS

PDF

74.1 KB Created: 2021-06-09 07:55:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 6a1ad96f5332d0b2c5a721bdf77b45a7 SHA-1: 075cddc6bd1940c14c0c5c6357d2340713a73271 SHA-256: c662dc76b1f52f0678c2438ffdaee7152beee3a1c425384f7cd89164397adf10
156 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The document contains numerous external links, many pointing to compromised WordPress sites, suggesting it functions as a link farm or phishing lure. The presence of 'subject pronouns online exercises' in the document body is a common social engineering tactic to disguise the malicious nature of the file.

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://philabc.ru/uplcv?utm_term=subject+pronouns+online+exercises PDF link annotation
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4e45c10c99---niluziwamoxobu.pdfIn PDF document text
    • http://amon-syotengai.com/userfiles/file/gafimuduzexizasorokir.pdfIn PDF document text
    • http://aihyang.com/userfiles/file/24874101716.pdfIn PDF document text
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/sovhiqtfgnknb1k09kun7177v1/xozaguzeboxefinemat.pdfIn PDF document text
    • https://www.cibaospalaser.com/wp-content/plugins/super-forms/uploads/php/files/q0fmlg4tgmqahqpmcm2qicq34v/judusafegowozavowi.pdfIn PDF document text
    • http://musiconthebay.org/clients/2/26/269dd5bc96e197da989a8dccc71442af/File/70075800727.pdfIn PDF document text
    • http://php-lounge.de/userfiles/file/93058342483.pdfIn PDF document text
    • http://firewheels.pe/userfiles/file/46529629899.pdfIn PDF document text
    • https://yildizwebpaket.com/calisma2/files/uploads/jerixunofewil.pdfIn PDF document text
    • https://girilawfirm.com/content_files/files/sopokusibixedibanu.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/1609239b6d8474---76206601484.pdfIn PDF document text
    • http://www.rotudavid.com/ckfinder/userfiles/files/vikerepimekegalowatedore.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096713eeec17---47486313800.pdfIn PDF document text
    • http://homenet-spb.ru/userfiles/file/98106717777.pdfIn PDF document text
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607efcc1e341a---28116841381.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/gr7i4quuetfd6kja0s0mvbtb37/sonokuve.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://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_off0000cda7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDA7 5104 bytes
SHA-256: cef6d99f7db47226c85da13a1d7783d81ff3fdf77a5ad4c3ae53d33c2f7be8ff
font_01_sfnt_off0000df1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF1D 11772 bytes
SHA-256: 7c7dace1bb0796f97f7e14021aae089e1da1f31a3e0de9756467ddaef24939b5
font_02_sfnt_off000105e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105E8 16204 bytes
SHA-256: a95eff378c135b1ab40d10b3cd1da1bafbc07f86005f57898d079c90d712ddbd