Malicious PDF — malware analysis report

Static analysis result for SHA-256 53bd4ca41b79a0d1…

MALICIOUS

PDF

90.8 KB Created: 2021-08-03 04:21:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 4b8504952622ff8e4ed922410d609be8 SHA-1: 10c6c99ac0eae91ab88914feeab6c29bad86d854 SHA-256: 53bd4ca41b79a0d10e8c31114323ed7f6c074b582f9eed76eda538b6cc704f7c
156 Risk Score

Malware Insights

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

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains a link farm pointing to multiple PDF files hosted on compromised WordPress sites, suggesting a phishing or malware distribution campaign. The presence of numerous external URIs and link farm heuristics indicates a deliberate effort to obscure the final malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://njsolarpower.com/wp-content/plugins/super-forms/uploads/php/files/0f60b2af896199c8127a5598e0f6e173/7160781752.pdf In PDF document text
    • http://nebovsem.ru/app/webroot/files/files/93637590779.pdfIn PDF document text
    • http://1960ihs.com/clients/e/e0/e0b58928a48036c9af8d6cfc9cffdd99/File/kagirogo.pdfIn PDF document text
    • https://aljuboori.com/userfiles/files/69439770366.pdfIn PDF document text
    • https://airshow-bg.com/file/tapezupefudi.pdfIn PDF document text
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/b9124f0869ce55eeca8492b2656b9992/votojogokekegoderoxitem.pdfIn PDF document text
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/4f57497312632a25d4e4c7747c4ddd38/nizopoxavelotaleraxa.pdfIn PDF document text
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b1a5aaea750---pokaz.pdfIn PDF document text
    • http://hertzlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/82706825017.pdfIn PDF document text
    • https://clubelsendero.com/img_pag/file/88979645125.pdfIn PDF document text
    • https://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/1c456765d3b26d3471ab8e6dd3cf44fa/tawokotiludopesa.pdfIn PDF document text
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ee9085871ed---gasupasilizekagaxiruviw.pdfIn PDF document text
    • https://seataclighting.com/wp-content/plugins/super-forms/uploads/php/files/8f83d2cb165302cc9b3df8986d0787c6/katugadepitiwizigakudisu.pdfIn PDF document text
    • http://thedreams.cz/files/21591441187.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160850c886fb6e---83660721596.pdfIn PDF document text
    • http://businessvaluationapp.com//fck_files/file/dekeri.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/160852ee645bc9---40113226468.pdfIn PDF document text
    • http://thechelseaff.com/user_uploads/files/wofamipuvi.pdfIn PDF document text
    • https://amalighting.com/wp-content/plugins/super-forms/uploads/php/files/4f38ac884ddd25c558143f8cdd85632b/81453728359.pdfIn PDF document text
    • http://maginsaatmetal.com/resimlerfiles/24021159899.pdfIn PDF document text
    • http://itaindustrial.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b4c110755a2---52213436535.pdfIn PDF document text
    • http://www.asslar.de/downloads/9506865266.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/3cdefd9fa647f966b6e6caa8ee0f1beb/74394368031.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=can+you+cook+costco+mac+and+cheese+in+a+crock+potPDF 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_off0000fdd2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDD2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000115e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115E9 11068 bytes
SHA-256: ab844b36b6191d21e3473d92f6e8da06c8b8bed72d71f4e9ce261a1a302eb52d
font_02_sfnt_off00012f95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F95 17320 bytes
SHA-256: 9fd61084a6da49e8a08d6b987d2967bf729159d1b9590129a1db669058db9434