Malicious PDF — malware analysis report

Static analysis result for SHA-256 436ea6ce145917a2…

MALICIOUS

PDF

73.2 KB Created: 2021-09-12 14:12:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: b20790dc992b1b92d0d81d14717bb862 SHA-1: a2aafe86e5f67b640f45efb737242dbeb883e48d SHA-256: 436ea6ce145917a2893cc7dc30e478b744cc563d526b2a821b8f6ca102d84215
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised WordPress uploads and disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links. The document body is heavily obfuscated and appears to be metadata from wkhtmltopdf, providing no direct user-facing content but confirming the file's nature as a generated PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 https://laborke.ru/uplcv?utm_term=thop+tv+apk+download+free PDF link annotation
    • http://scouttautomotive.com/editor_uploads/system/files/nives.pdfIn PDF document text
    • http://champagne-marc-chauvet.com/images/files/33341460016.pdfIn PDF document text
    • http://taociren.com/upload/file/210906033303025126280apiebsi6j.pdfIn PDF document text
    • http://cen7dias.es/userfiles/files/boxeveludukomixuw.pdfIn PDF document text
    • http://artstudiodesign.it/userfiles/files/57315942553.pdfIn PDF document text
    • https://yukkumpulgroup1.com/contents/files/tifusunulanogonug.pdfIn PDF document text
    • http://nt-module.ru/ckfinder/userfiles/files/wokelimevoxiwumak.pdfIn PDF document text
    • http://gld-lining.com/user_img/files/85649262648.pdfIn PDF document text
    • http://www.tivafa.hu/upload/file/jipaloj.pdfIn PDF document text
    • http://chuabenhxuongkhop24h.com/images/files/zipagafolabi.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ecdf48c6d7---nufataketemujevo.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613848b99e4b7---40694135145.pdfIn PDF document text
    • http://elard-group.com/ckfinder/userfiles/files/telekowapunavudexebosup.pdfIn PDF document text
    • http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132edde92c76---3838219692.pdfIn PDF document text
    • http://kbchina.de/upload/18891766866.pdfIn PDF document text
    • http://4998horo.gmmwireless.com/contents/files/44951432344.pdfIn PDF document text
    • http://ud2-140.com/files/kuniziselo.pdfIn PDF document text
    • https://ximatinhdongnai.com/app/webroot/files/images/pages/files/14768473815.pdfIn PDF document text
    • http://nuk-amro.de/userfiles/file/kabavajigofubuturevetetif.pdfIn PDF document text
    • https://dailyhondaotomientay.com/upload/files/takoxurusenej.pdfIn PDF document text
    • https://siroyensao.com/upload/files/debajepux.pdfIn PDF document text
    • http://1night2day.com/UserFiles/file/doxowopuwonuton.pdfIn PDF document text
    • 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_off0000bdc6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBDC6 10540 bytes
SHA-256: c99e450d1eb536bf9657d3a92181dd903087e8abc2e03cb12500e6fddfcd5901
font_01_sfnt_off0000d5d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5D1 16176 bytes
SHA-256: 27d9919d9c1a4bb3de67592dedbc0be8964c074877013025fe8293b5ea2c7327
font_02_sfnt_off0000ff14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF14 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1