Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f823490df4601a6…

MALICIOUS

PDF

70.4 KB Created: 2021-06-23 05:16:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 0bab57cf36203b232b70d86395092cfe SHA-1: 4390b03262a91af231b45330183ffe4a49f34fbf SHA-256: 4f823490df4601a6b2a166bdb6e336d96ea54eaf302cd99aacf20e71af3befc5
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. Several heuristics point to the document being part of a link farm hosted on compromised or disposable domains, suggesting it's designed to redirect users to malicious content. The presence of numerous embedded URLs, many pointing to compromised CMS upload directories, further supports this. No scripts were extracted, but the overall structure and URL patterns are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/160962fb12f07e---44562522823.pdf In PDF document text
    • https://dianthusindustrial.com/resimler/files/mamileduxokuketovopo.pdfIn PDF document text
    • http://flygarfield.net/userfiles/file/silimanufavalor.pdfIn PDF document text
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/v83qfmam33ee787u4p39ao5br1/39703906454.pdfIn PDF document text
    • http://myconnect-thailand.com/image/upload/File/balifuwonigavitibonugos.pdfIn PDF document text
    • http://beytarimcilik.com/admin/editor_resim/file/69787078398.pdfIn PDF document text
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/9cadd1b68703c5741b6d5abc1e3d68d5/bixukovudumuretilu.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/160bbae291af44---vaferakederojob.pdfIn PDF document text
    • https://asthasupermarket.com/userfiles/file/sakunonakobajavewelofuzon.pdfIn PDF document text
    • http://bettaletroom.com/file_media/file_image/file/28263467542.pdfIn PDF document text
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/16091d64149884---15357073276.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608c7c1be2ee9---zedufotogedizejeb.pdfIn PDF document text
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160742d58a23c3---28634927819.pdfIn PDF document text
    • http://krevue.cz/UserFiles/File/58762956968.pdfIn PDF document text
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b54bd12527---97476958176.pdfIn PDF document text
    • https://semineebrasov.ro/printuri-fi/files/91296591368.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=motor+blower+assembly+pdfPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d73b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD73B 5524 bytes
SHA-256: c0e2d13fa48f26fcdb9eb747f27be775cdaf1c1c9a7f23b5375a218f7b2eec92
font_01_sfnt_off0000ea0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA0D 10568 bytes
SHA-256: 80a1bf013318ed32780590fdb61859aea9798f6ccd60eaaabc7a8fba3a17dc7f