Malicious PDF — malware analysis report

Static analysis result for SHA-256 9c23cd4ec6e80f2c…

MALICIOUS

PDF

87.0 KB Created: 2021-07-05 07:07:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: ac6aa688fbcad85f2f2667c94818e42a SHA-1: 24628a14c4a120e350f96a80d2cb103cf137b618 SHA-256: 9c23cd4ec6e80f2ce2f2ca8be5a1654cc2ee308c9e18bcad0c2152d0cd551646
236 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1553.005 Security Software Installation

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The document contains instructions to disable security software, a common tactic to bypass defenses and facilitate the download of further malicious content. Numerous links to external PDF files hosted on compromised WordPress sites and disposable domains suggest a link farm used for distributing malware or phishing content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 8

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • Security software disable instruction high SE_SECURITY_BYPASS
    Document instructs the user to disable antivirus or security software — unusual for ordinary documents and high-risk in an unsolicited file
  • 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://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/vdsp6dfkkn03jmm43ne6tekkoi/66067139676.pdf In PDF document text
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/d9e47a7b494992b906c7fa2273c39010/87206181411.pdfIn PDF document text
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/2233eca61bdbc26140011379ba063e06/49639766478.pdfIn PDF document text
    • http://atek-ent.com/upload/file/boviro.pdfIn PDF document text
    • https://mangonebike.com/uploads/file/dixot.pdfIn PDF document text
    • https://vuaship.com/wp-content/plugins/super-forms/uploads/php/files/6l05041v0t0l1j024i3vnr262i/85297587652.pdfIn PDF document text
    • https://etadelloro.it/images/file/wezojetexubenar.pdfIn PDF document text
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1609ee5e9da17f---91109008551.pdfIn PDF document text
    • https://dubigroup.com/admin/fckeditor/editor/filemanager/connectors/upload/file/porulusegite.pdfIn PDF document text
    • http://premsaktidal.in/userfiles/file/vonosilupavefirivovenigej.pdfIn PDF document text
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160822b19bfb41---88758436243.pdfIn PDF document text
    • https://lecormier-menuiserie.com/www/upload/files/54908633804.pdfIn PDF document text
    • http://guyfamilyreunion.com/clients/41950/File/xefekabegimogegezisoza.pdfIn PDF document text
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d6a67f3777---71603088671.pdfIn PDF document text
    • https://www.ltgpartners.com/wp-content/plugins/super-forms/uploads/php/files/f4550a7a7ad48b9478ea9483408a3a73/safitatuduvotogaled.pdfIn PDF document text
    • https://awlights.com/wp-content/plugins/super-forms/uploads/php/files/4c3977867240d4ebe04a45cdf3f92c57/56847613292.pdfIn PDF document text
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/5qffrc5ghtjj7h1hqprodmovt0/kurarasivogetexewab.pdfIn PDF document text
    • https://acethamessecurity.co.uk/wp-content/plugins/super-forms/uploads/php/files/cc5045cf4d5fb1ffeea23e9be4f21fd0/98815694568.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/1606f648cb7da5---1490491149.pdfIn PDF document text
    • https://medicinasolidale.org/wp-content/plugins/super-forms/uploads/php/files/2f5948ce34be516433f35faa16e58031/28817763577.pdfIn PDF document text
    • http://aire-limpio.com/img/editor/file/zakitujekoteb.pdfIn PDF document text
    • http://brighterhealthcare.co.uk/wp-content/plugins/super-forms/uploads/php/files/17o8ngiant21k957751ojea5fv/fapakusaxotol.pdfIn PDF document text
    • http://www.danvillern.com/wp-content/plugins/super-forms/uploads/php/files/apd7tp5r3go9vqo4h1kdo5qtn1/girubimuv.pdfIn PDF document text
    • https://qualitylightsolutions.com/wp-content/plugins/super-forms/uploads/php/files/7afddcecde9dfdd3e26495f68046ca8c/89504314898.pdfIn PDF document text
    • http://beetsom.com/PROGRAM_FCKeditor_UserFiles/file/44882634860964fef0baf4.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=use+of+mould+board+ploughPDF 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_off0000f0ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0EA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010901.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10901 10896 bytes
SHA-256: 662fe8fa06bf23c17f609104d632ecba8062db989fd06baced3a5ad2bb6e76e1
font_02_sfnt_off000121bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121BF 17092 bytes
SHA-256: 7f2a2c35e8310876ce4806fb5d0ee7687b1174a5834566ad84c04ddb40a88ac6