Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f13d35a016140fb…

MALICIOUS

PDF

81.1 KB Created: 2021-10-06 03:26:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 84a7bc2610c0cc5a9bb326d3c7731bb1 SHA-1: 181feea8471d5aca83a3ffb09c1a5a33da597b92 SHA-256: 4f13d35a016140fb6d262eb4c5fa42e174f7e03bd90a4a1de0d50bdaa73323b3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous external links, many pointing to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users. The PDF structure and embedded links are consistent with phishing or malware distribution lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://krisoc.ru/uplcv?utm_term=the+king+of+queens+season+7+episode+12 PDF link annotation
    • https://vozilasavozacem.rs/files/robisutevubujasinilanob.pdfIn PDF document text
    • https://mysilo.com/upload/ckfinder/files/daxedanezevigutewuj.pdfIn PDF document text
    • http://residencelesaline.it/userfiles/files/jisizemadezodubapagim.pdfIn PDF document text
    • https://free-spirit-city.eu/uploads/wysiwyg/files/vulemuzubiribojibosizap.pdfIn PDF document text
    • http://thainightjob.com/ckfinder/userfiles/files/88569815154.pdfIn PDF document text
    • http://dpholding.ru/uploads/files/zebidosinepatalaten.pdfIn PDF document text
    • https://elnativocoffee.com/silver/upload/files/zafemutuborigapedoji.pdfIn PDF document text
    • http://pololanna.com/user_img/files/70866194666.pdfIn PDF document text
    • https://nocenzura.space/web/img/podborky/files/vodew.pdfIn PDF document text
    • https://laplacedesstores.com/upload/file/82763610329.pdfIn PDF document text
    • http://andreevmag.com/wp-content/plugins/super-forms/uploads/php/files/0077abdc748eef6833f6d348e71d6704/37832981463.pdfIn PDF document text
    • https://tekstilkentrehber.com/upload/ckfinder/files/2879163703.pdfIn PDF document text
    • http://compagniaviaggi.gattinonimondodivacanze.it/themes/userfiles/files/jizabifuxexo.pdfIn PDF document text
    • https://begili.com/uploads/image/files/kiwiturozoxegukozatax.pdfIn PDF document text
    • http://bagodilovaspark.hu/userfiles/file/nekusukunuvarotapotubuvu.pdfIn PDF document text
    • http://nadiadsa.org/userfiles/file/nuwanaserivedarujas.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/34b97509f9dcf42f4dd5eaf0118ef781/ninowufi.pdfIn PDF document text
    • https://hmjrgoldhockey.org/wp-content/plugins/super-forms/uploads/php/files/07b07a515c60c4e8a9361224c3ebec62/xuwoxof.pdfIn PDF document text
    • https://curvy.tw/upload/files/tobefuvusamugul.pdfIn PDF document text
    • http://daedukgs.com/admin/fckeditor/data/file/20211003233550.pdfIn PDF document text
    • http://haiannweb.com/uploads/files/17096498565.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_off0000d4e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4E2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ecf4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECF4 18544 bytes
SHA-256: 96533f355ac3a1825f2fcce83476e3b5f956816f2821bddfd7348ba175ffc115
font_02_sfnt_off00011d24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D24 11056 bytes
SHA-256: 1ff56e230d6e55aa2e10cf7acec5bfeb9e657b24b2e33e4ad43bf1e4752a6a8f