Malicious PDF — malware analysis report

Static analysis result for SHA-256 0685c3eb39449fb5…

MALICIOUS

PDF

74.8 KB Created: 2021-09-07 13:53:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: b3c341c8fdb7314c8d069da199157721 SHA-1: 923294b9334172513585fda30aed2a082283aa45 SHA-256: 0685c3eb39449fb54a8d63d488a201d96c2506208b526ae0ae3e947af667b2e7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous embedded URLs, many of which point to compromised CMS upload storage or are part of link farms on disposable hosting, suggesting a phishing or malware distribution scheme. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics indicates attempts to obscure the true malicious destination. Although no scripts were explicitly extracted, the PDF structure and embedded links are indicative of a phishing lure, likely using a CV template to entice users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9824

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 http://thevisionkharj.com/userfiles/files/44863733313.pdf In PDF document text
    • https://augsburger-dartliga.de/uploads/file/82621195700.pdfIn PDF document text
    • https://kiemtoandongnghi.com/public/plugins/ckfinder/userfiles/files/merezowofemidaxasem.pdfIn PDF document text
    • http://securitydirect.it/wp-content/plugins/super-forms/uploads/php/files/128b8e83d87a3c9ba55c73dbfd24c649/33608254966.pdfIn PDF document text
    • https://vnmmalta.com/userfiles/file/zabesedegasumu.pdfIn PDF document text
    • http://runningrhinelanderrabbitry.com/clients/875187/File/90438972618.pdfIn PDF document text
    • https://almuhja.net/ckfinder/userfiles/files/97898352967.pdfIn PDF document text
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2313576f4f---jotiradoraripozu.pdfIn PDF document text
    • http://anoh.net/pds/userfiles/files/35844247143.pdfIn PDF document text
    • http://khunghinhdepphuctin.com/media/ftp/file/43229034727.pdfIn PDF document text
    • http://munnarinfo.in/userfiles/file/43371584118.pdfIn PDF document text
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086275364062---pubilivetamogusupizagejit.pdfIn PDF document text
    • http://agcslohian.com/userfiles/file/18434671955.pdfIn PDF document text
    • https://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/b6690f9b8db6883f765570d31fed5325/jewoxujesanez.pdfIn PDF document text
    • https://aimara-bg.com/userfiles/file/xuwuwesomopozikofaviwij.pdfIn PDF document text
    • https://avgdesign.com/userfiles/file/winudoz.pdfIn PDF document text
    • https://www.baileysmilk.com/wp-content/plugins/super-forms/uploads/php/files/2db53fd3ace4cdb27de2b598f590448e/18261661042.pdfIn PDF document text
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612c41a1d7420---40246763164.pdfIn PDF document text
    • https://adsbudget.net/userfiles/file/91576399627.pdfIn PDF document text
    • https://prana.video/wp-content/plugins/super-forms/uploads/php/files/00l3sbi9ljd0encdahsdnp2q3d/duzaparenewegof.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/65672e3aa8aee47fa64d5dad09e0b2c7/dutipakavameravog.pdfIn PDF document text
    • http://tranhdaquydep.vn/upload/files/17722221873.pdfIn PDF document text
    • http://casinodanmarkjackpot.dk/userfiles/file/52006636374.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/svl8h8du7gqfn4av171ppt4341/sokitomenevilav.pdfIn PDF document text
    • https://condicionamentofisico.com/arquivos/file/94284832520.pdfIn PDF document text
    • http://geoplan.su/userfiles/file/jokajikadizozuso.pdfIn PDF document text
    • https://used-machinetools.ro/app/webroot/files/userfiles/files/jojujedixigosowobe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=cv+template+uk+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://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_off0000c73c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC73C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000df4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF4E 15844 bytes
SHA-256: d8abc2c44db5c7bab2ecfb203bbca1f34fe6a6b4d142d54a7ade8671733814d4
font_02_sfnt_off000107a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107A0 10364 bytes
SHA-256: 7eb7a439ba8deee7d21a538dd326a986ab726df74ce90264ac374def951c0bfc