Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4afb816b5376737…

MALICIOUS

PDF

79.7 KB Created: 2021-09-05 20:07:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: 37c0ef250185d13099f6b0619e87597a SHA-1: 5fe12b60bbf63a87280f552635e01a7e63534f52 SHA-256: a4afb816b537673730423bee2ac13f971412050b67000d889bea58212b0e9639
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c964305a3c---sexunibage.pdf In PDF document text
    • http://artdental.hu/editor_up/75830058328.pdfIn PDF document text
    • http://reklama-kemerovo.ru/files/files/32039910224.pdfIn PDF document text
    • https://rugsinc.in/UserFiles/files/foxutimuto.pdfIn PDF document text
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608558ed95c52---18448459279.pdfIn PDF document text
    • https://www.hintonassociates.com/wp-content/plugins/super-forms/uploads/php/files/84aa864437bd0e2a2e95bdba363b4bfb/15289949279.pdfIn PDF document text
    • https://chp-travel.ir/data/file/25694582465.pdfIn PDF document text
    • http://alacarte-grafik.de/userfiles/file/feximixujemefutap.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/97649647792.pdfIn PDF document text
    • https://vegas-shop.net/uploads/files/39373338932.pdfIn PDF document text
    • http://airconbank.com/upload/fckeditor/file/79829035655.pdfIn PDF document text
    • http://sentezetutmerkezi.com/upload/ckfinder/files/70145861160.pdfIn PDF document text
    • http://zatexpress.com//upload/userfiles/files/wulojapesesel.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e06ca0ca80---darakolinopumavuveb.pdfIn PDF document text
    • http://sapaelitehotel.com/webroot/img/files/fikasiduziregimemute.pdfIn PDF document text
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/2f4ab800ee3bd17500ad2fbdec8662cb/38056945911.pdfIn PDF document text
    • http://diennuocdanang.com/uploads/image/files/94793869417.pdfIn PDF document text
    • http://biotop-zamosc.pl/userfiles/file/25084048961.pdfIn PDF document text
    • http://g-shocktou.com/user_file/file/laziv.pdfIn PDF document text
    • http://k2plusinterior.com/userfiles/82726122477.pdfIn PDF document text
    • https://pavimenti.pl/web/uploads/files/4715969917.pdfIn PDF document text
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c77f9210612---padaxoropora.pdfIn PDF document text
    • https://laser-arena.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1606e46107ebf9---kegitopi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=renatus+nova+business+plan+pdf+downloadPDF 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_off0000d3b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3B7 10828 bytes
SHA-256: 08919ccc6ec16bcea0703f2fd57a66d87d7041afb07de5b4dc275e1ba26f90fd
font_01_sfnt_off0000ecac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECAC 17176 bytes
SHA-256: 759bf644c955b2c7c28b348b18339086d20c5c77f698e97868d482ce3bffc501
font_02_sfnt_off0001190c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1190C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1