Malicious PDF — malware analysis report

Static analysis result for SHA-256 52710d81cb5a8883…

MALICIOUS

PDF

75.3 KB Created: 2021-09-17 01:13:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 3e6b932a1ca8d948946632ec2a22bf48 SHA-1: 62a2aa084b44d0ac08824e64d218d7143c32d046 SHA-256: 52710d81cb5a8883dee18cf8df8f1fcf2cde09f0f98ef69bddfb4a1b77c273c5
156 Risk Score

Malware Insights

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

The file was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to compromised CMS upload storage or are part of a link farm on disposable hosting. The document body is unreadable, but the heuristics indicate a strong likelihood of phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://mimzyonline.com/userfiles/file/16166633299.pdf In PDF document text
    • https://ordermorestuff.com/cmsCart/upload/file/xodofexoban.pdfIn PDF document text
    • https://showdetango.com/bafa/userfiles/file/80804720756.pdfIn PDF document text
    • https://tezerwatch.com/file/upload/files/09-01-21-51-56-54.pdfIn PDF document text
    • https://biomedchita.ru/imeg_master/file/99898840924.pdfIn PDF document text
    • http://pileshoppen.dk/userfiles/file/wujigibadavefomarezoneb.pdfIn PDF document text
    • http://kamennykoberec.eu/editor_uploads/system/files/65087121343.pdfIn PDF document text
    • https://rajakedua.com/contents/files/80641861846.pdfIn PDF document text
    • http://www.dreamstoreonline.es/ckfinder/userfiles/files/nemaxazezikamifenadadoro.pdfIn PDF document text
    • http://www.octopus-quatuorvocal.com/ckfinder/userfiles/files/71863780205.pdfIn PDF document text
    • http://teamwork-poetschke.com/ckfinder/userfiles/files/4908778192.pdfIn PDF document text
    • http://reliancefla.com/admin/images/file/galediz.pdfIn PDF document text
    • https://www.sesc.com.ua/wp-content/plugins/super-forms/uploads/php/files/btehjf8l5q0pneiao5b1empo67/rizuguzopuf.pdfIn PDF document text
    • https://zlato-invest.cz/upload/files/80308644127.pdfIn PDF document text
    • https://baruipur.org/ckfinder/userfiles/files/35681804724.pdfIn PDF document text
    • http://www.larucheapain.fr/ljk/file/regubibudaxidugijubud.pdfIn PDF document text
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16140ed42d8b1c---nelebibusejuresexujotimi.pdfIn PDF document text
    • https://ecoolteh.eu/galeria/file/fududivu.pdfIn PDF document text
    • https://aquarell.ro/userfiles/file/pupaneginunudegutikiguxa.pdfIn PDF document text
    • http://pphjako.pl/userfiles/file/36236740993.pdfIn PDF document text
    • https://mepho.hu/ckfinder/userfiles/files/kilomibuwo.pdfIn PDF document text
    • http://yaqeen-eg.com/userfiles/file/zajowapajusafawobezol.pdfIn PDF document text
    • http://baovecongtruong.com/upload/files/56886359477.pdfIn PDF document text
    • https://ivfnna.gr/wp-content/plugins/super-forms/uploads/php/files/6f767c84f048414018ef67f53906942c/fejubowamokugolimenubaja.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=cheat+code+for+coin+masterPDF 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_off0000c31d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC31D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000db2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB2F 17024 bytes
SHA-256: b8c9222ff06a982ea411a0b1a6531061ab6eaec2a6900efda42fca5248463470
font_02_sfnt_off0001071a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1071A 10728 bytes
SHA-256: bf4f6852f896056c230538aed260d8435cf0604a29c9339d4f8b6dae916c1a50