Malicious PDF — malware analysis report

Static analysis result for SHA-256 d310d11ef5072f13…

MALICIOUS

PDF

73.4 KB Created: 2021-09-16 04:47:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 609c783af22cacc6baa530e874fd989c SHA-1: 3206465105615df8f7f896c8bfd9affbd6551423 SHA-256: d310d11ef5072f1392a64eee900c8ba2c51de01170ce7d83f063e0ecb0621729
96 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users to potentially malicious content. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent. No scripts were extracted, and the document body was unreadable, so the primary attack vector appears to be social engineering through link redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 5

  • 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://cesiedizioni.com/userfiles/file/4396630311.pdf In PDF document text
    • http://assytekservizi.com/userfiles/files/94735210732.pdfIn PDF document text
    • http://jinsonmetal.com/Upload/file/nivibunubigasimadafavunu.pdfIn PDF document text
    • https://coverline.ro/userfiles/file/38424302730.pdfIn PDF document text
    • http://abwalabamaave.com/uploads/files/16392812503.pdfIn PDF document text
    • http://www.americaninvest.net/upls/files/xuxet.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161411494845e9---mazifanasilem.pdfIn PDF document text
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613754a4eed73---lepigiwivesogiwik.pdfIn PDF document text
    • http://tinhdauvietnam.vn/upload/files/voxafogemetiwefurepaniwab.pdfIn PDF document text
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1613990e1638cb---levori.pdfIn PDF document text
    • http://netcentricnj.com/ckfinder/userfiles/files/negixunumuron.pdfIn PDF document text
    • https://greenturtleproductions.com.au/wp-content/plugins/super-forms/uploads/php/files/9a485ef0f6bca3881ab2a32c30a7718e/81100083905.pdfIn PDF document text
    • https://triatlonshop.cz/userfiles/file/mofodeguzetapigezazajaje.pdfIn PDF document text
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/9e85fef7f252579c6d66132679d65c39/67729902855.pdfIn PDF document text
    • https://grandhotelushba.com/userfiles/file/zitididodifomesep.pdfIn PDF document text
    • http://cafehinglung.com/uploads/files/gigowipube.pdfIn PDF document text
    • http://formpart.com/upload/ckfinder/files/89611097359.pdfIn PDF document text
    • http://nbc.com.vn/ckfinder/userfiles/files/25981326854.pdfIn PDF document text
    • http://balbu.hu/uploads/news/file/31335648282.pdfIn PDF document text
    • http://sosonomo.com/ckfinder/userfiles/files/8934084489.pdfIn PDF document text
    • http://drkoopman.nl/cmsimages/file/52700714229.pdfIn PDF document text
    • http://word.mn/uploads/assets/54935904145.pdfIn PDF document text
    • http://www.binghan.my/userfiles/file/kofemarakuxikisoxitudumet.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=android+torrent+search+appPDF 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_off0000bca7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBCA7 16640 bytes
SHA-256: 16a561598c5190acd7a14f571d2b8c75f22150c7cbc4ecdb725e14407ee2bf52
font_01_sfnt_off0000e7e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7E4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fffb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFFB 10544 bytes
SHA-256: 4db78e2fb4f16ce94cf0bd6e008fc66f5e364bfb7fc14ba4bfc0a84bf284a72d