Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef7d78edd766ffd4…

MALICIOUS

PDF

89.3 KB Created: 2021-10-13 04:49:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-03
MD5: ebcd1fd21cd92a10dc1f3cde7b93f2db SHA-1: 2739b850d5583977c1ff88459624328b0a51c0ac SHA-256: ef7d78edd766ffd40d82d03a48621bb9fafc0363d330160064ab86c851b29364
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, with many embedded URLs pointing to potentially compromised or disposable domains. This suggests the document is designed to lure users to external sites, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://queure.ru/uplcv?utm_term=what+does+fse+stand+for PDF link annotation
    • http://saigonford3s.com/uploads/2021-09-08/images/files/38211698011.pdfIn PDF document text
    • https://rizecanreklam.com/images/file/jexejixuxisurereg.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/16150dc9e417f8---56596033306.pdfIn PDF document text
    • http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/61897070.pdfIn PDF document text
    • https://christianbelieversmatrimony.com/web/christiansbelieversmatrimony/photos/ckeditor/files/26520519281.pdfIn PDF document text
    • http://saopauloairporttransfers.com/ckfinder/userfiles/files/52501229213.pdfIn PDF document text
    • http://laboratoriodiprogettazione-ve.it/userfiles/files/pefabijonu.pdfIn PDF document text
    • http://mezon.jp/userfiles/file/tonezesi.pdfIn PDF document text
    • http://www.cenlaenvironmental.com/siteuploads/editorimg/file/wijexukis.pdfIn PDF document text
    • https://www.prowallpanama.com/wp-content/plugins/super-forms/uploads/php/files/df2c0a9472525479eb45d0061b36e059/27637184691.pdfIn PDF document text
    • http://worldtile.net/jangheung/userfiles/file/wisizokefiv.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/5sm6mg3voel7b5njn5bmfodbd7/fijubariwenoze.pdfIn PDF document text
    • http://namuvaldymas.lt/userfiles/file/rowisamonumimiza.pdfIn PDF document text
    • https://sapporopools.com/contents/files/14887639276.pdfIn PDF document text
    • http://texinpack.com/uploadfile/file///2021100915464175.pdfIn PDF document text
    • http://gongotour.com/FileData/ckfinder/files/20210927_0D407293DE663A80.pdfIn PDF document text
    • http://zrdb-drogbud.pl/Upload/file/rofusiribaribi.pdfIn PDF document text
    • https://opremazabebe.me/userfiles/file/xixizu.pdfIn PDF document text
    • https://www.restaurant-latableedevercel.com/ckfinder/userfiles/files/58519573971.pdfIn PDF document text
    • https://www.zochrot.org/ckfinder/userfiles/files/dozovulijugigarubugez.pdfIn PDF document text
    • http://hk-keber.de/images/file/22774445820.pdfIn PDF document text
    • http://kodemari.info/data/files/jegekejexazinubajijew.pdfIn PDF document text
    • https://acryl-bg.com/userfiles/file/lopukoxofefuzatobawiruden.pdfIn PDF document text
    • http://dui-antidote.com/images/userfiles/file/kufixapupejozekidefuw.pdfIn PDF document text
    • http://jessie.vn/images/ckeditor/files/95079933557.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_off0000f462.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF462 10304 bytes
SHA-256: 2adfae943907626787fe1e3ebc5ac241ace6da6ba1b31e3a4b2ec0195425932f
font_01_sfnt_off00010b96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B96 20108 bytes
SHA-256: 74650a7304c137d06a914c1ae8f92e3e169d1463c7ce10148eb3b3f017cc7c57
font_02_sfnt_off00014006.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14006 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1