Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd337db6fd9f2525…

MALICIOUS

PDF

77.4 KB Created: 2021-10-06 01:56:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: cd6ead2b974bc9db2a8c8d683ae7cce8 SHA-1: cd52ad6e69bef074ae0e0a8c3a323d8095048e61 SHA-256: cd337db6fd9f2525f6019cfabbb91bd964ca583ee36dffbd82a872f74b15b21b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. The document body is heavily obfuscated and unreadable, providing no direct content clues, but the heuristic firings and URL analysis point to a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://gulf-rope.com/images/bulk_images/files/zotanowobime.pdf In PDF document text
    • http://hairtransplantmangalore.com/uploaded_files/userfiles/files/43855331564.pdfIn PDF document text
    • http://escalierdurire.fr/ckfinder/userfiles/files/solexujozajamoviteko.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/2306bf72ae810431a83ccac85cdb6620/86908151504.pdfIn PDF document text
    • http://cssh.es/img/file/21578015577.pdfIn PDF document text
    • http://miamiwars.pl/wp-content/plugins/super-forms/uploads/php/files/369f221ccdff22792a0e712e9c1d4be7/97209325405.pdfIn PDF document text
    • http://avesta-hmora.boj.se/uploads/userfiles/files/3678803580.pdfIn PDF document text
    • https://webdatedepot.com/userfiles/file/61105297399.pdfIn PDF document text
    • http://pspectr.ru/userfiles/file/66496288563.pdfIn PDF document text
    • http://xn--12cfu9bc1efac9a9azfdsb7b9d1f0j.net/ckfinder/userfiles/files/95181256680.pdfIn PDF document text
    • http://qlionshousing.ca/userfiles/file/9384925294.pdfIn PDF document text
    • https://full-flavors.com/img/Data/file/5818082189.pdfIn PDF document text
    • https://vicareyou.com/userfiles/file/peguxeboroxufinurikutojid.pdfIn PDF document text
    • http://studiomanzella.com/userfiles/files/61866864957.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/1614a369170b56---4054062507.pdfIn PDF document text
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/16155674e673f1---3836330503.pdfIn PDF document text
    • http://vcelari.naceradec.cz/includes/ckfinder/userfiles/files/83052129977.pdfIn PDF document text
    • http://dj-maily.com/uploads/pages/files/dabunon.pdfIn PDF document text
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614463ddaaed0---8615295346.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=lecturer+in+business+managementPDF 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_off0000c857.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC857 10604 bytes
SHA-256: d573603bfb573d9a1bda6ead96b394923f22cea343ea02e3adda7b0cefc9efd6
font_01_sfnt_off0000e08e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE08E 18672 bytes
SHA-256: 211a29e452a4b27a895fed829b92c2697211eeeb2127b65a2ac1f354005f2390
font_02_sfnt_off000110ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110AD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1