Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8d5d6335079dd54…

MALICIOUS

PDF

92.9 KB Created: 2021-07-19 09:50:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 148a0a0dd27edf356d3678aee91073d3 SHA-1: 51f5226acf53de763c6526c838f6654efde51d9a SHA-256: b8d5d6335079dd5485bacd4164bd8720c18feb26edd4532c5fc4364f7ad3278a
156 Risk Score

Malware Insights

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

This PDF was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous links pointing to compromised WordPress upload directories and disposable hosting, suggesting it's part of a link farm designed to redirect users to malicious sites. The document body is heavily obfuscated and unreadable, indicating an attempt to hide its true purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://weblative.com/wp-content/plugins/super-forms/uploads/php/files/b9al8h2v7q795p1ahsuep1vdtp/milugumoruvo.pdf In PDF document text
    • http://sts-logistika.ru/wp-content/plugins/super-forms/uploads/php/files/bca1688e921910397579db85c225cc55/kuxogebabarukejaz.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/160a2f0529789f---44566642834.pdfIn PDF document text
    • https://www.hontoys.com.au/wp-content/plugins/super-forms/uploads/php/files/01776s7523hlrc54eco8ih4nlm/19076256738.pdfIn PDF document text
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/3da67e9f0939e96a6518bd9e6dc7de07/69620519394.pdfIn PDF document text
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/0142fef3013d968ba77ea161abd18e8c/kevakitedinolugitaxew.pdfIn PDF document text
    • https://mebelihome.ru/upload_picture/48076394123.pdfIn PDF document text
    • http://trevelsi.ru/ckfinder/userfiles/files/furexosusiwozigexoxofaw.pdfIn PDF document text
    • https://goldenparadisestsimons.com/wp-content/plugins/super-forms/uploads/php/files/a88b8a4198d0010c962bd818f5801097/66815388532.pdfIn PDF document text
    • https://brawlcall.com/ckfinder/userfiles/files/dotakuti.pdfIn PDF document text
    • http://www.loicadesacavem.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1609c5b066daff---kunenovemijetipe.pdfIn PDF document text
    • https://xistenze.com/files/files/gumixopewiduta.pdfIn PDF document text
    • http://munsusa.org/userfiles/file/20210716050851.pdfIn PDF document text
    • http://www.reroofingbrisbaneqld.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607fb402842f2---83564712771.pdfIn PDF document text
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608340e50b4b1---73880919502.pdfIn PDF document text
    • http://smartwealthhk.com/userfiles/35351795946.pdfIn PDF document text
    • http://thegioioto.store/upload/files/78654562288.pdfIn PDF document text
    • http://sushrutproctology.org/ckfinder/userfiles/files/xigaboxomexasazebun.pdfIn PDF document text
    • http://www.cheapmotorcycleinsurancepa.com/wp-content/plugins/super-forms/uploads/php/files/78itqi1r1tu1leh1vch6dpo8j1/nepezodusa.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/b1dcd9cb3da0c0a06ea13a535701b911/13345607484.pdfIn PDF document text
    • http://afghansolar.com/userfiles/file/43754362418.pdfIn PDF document text
    • http://neodev.space/wp-content/plugins/formcraft/file-upload/server/content/files/160c1bc705a7be---vurifepi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=multistep+checkout+for+woocommercePDF 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_off00010827.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10827 10752 bytes
SHA-256: 5e03f20b5c9e948a3afdff7c5eb0f3a60d4eb4aa906558b08c25db0f7715ead0
font_01_sfnt_off000120fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120FE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013910.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13910 17288 bytes
SHA-256: 5665fb3b6dfe13087cc72a5bd13e4ff1a1d8f655bfc2efdf3dd766645533271e