Malicious PDF — malware analysis report

Static analysis result for SHA-256 77fae6844a3b9502…

MALICIOUS

PDF

65.7 KB Created: 2021-06-13 01:45:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: b508ac79e8c39988a3a355de8f72508b SHA-1: f29d434a4cf044b4e258802a2bb4b8781fae837e SHA-256: 77fae6844a3b95026b9c376348a790493b4e03818faea6c7afa05ef7051744c8
156 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Numerous embedded URLs, including those hosted on compromised CMS upload storage, suggest a phishing or malware distribution scheme. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this, pointing to a link farm strategy.

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://synerhu.ru/uplcv?utm_term=avengers+2019+tamilyogi PDF link annotation
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/16092d262a669f---zedanidez.pdfIn PDF document text
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/rulokepafovo.pdfIn PDF document text
    • http://a-swiss.com/upload/userfiles/file/dopowusetamuvagusobema.pdfIn PDF document text
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfb6dce75fc---fewigemunuboxapil.pdfIn PDF document text
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16098cafe0b443---53682531759.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac48e4c0d0c---65977561669.pdfIn PDF document text
    • http://pcccphucvinh.com/upload/files/renakewini.pdfIn PDF document text
    • https://www.alignerco.ca/wp-content/plugins/super-forms/uploads/php/files/47d6b3dce9328be6b802f072a79c330b/45237089755.pdfIn PDF document text
    • https://plswa.com/wp-content/plugins/super-forms/uploads/php/files/c03fdfe3a93307a91bd2110e88243064/23345444238.pdfIn PDF document text
    • http://alexhofford.com/temp/files/file/80519328935.pdfIn PDF document text
    • https://htchninc.com/d/files/kogufozeguposimexoz.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607ea3f896abb---woveduwesowibolodeki.pdfIn PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607e0016370a3---guzowudata.pdfIn PDF document text
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/96c1c998553890065cb96f164918a30c/91786831002.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a9c5858188d---99256581153.pdfIn PDF document text
    • https://www.mnspineandsport.com/wp-content/plugins/super-forms/uploads/php/files/1a113bb4af4954d8e0b8e8cc5ed16a16/lewowofexubepeb.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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c362.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC362 5640 bytes
SHA-256: 02cb328ab1c11c8af478747cf0b98da3c2c08c98863a99a70e138fdb735afd23
font_01_sfnt_off0000d696.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD696 9988 bytes
SHA-256: 3258ee4cabfa8fb482f0ed78c467d9c0cfef436d03d675c974acc5b86dfe24f1