Malicious PDF — malware analysis report

Static analysis result for SHA-256 92539a9635bd83bc…

MALICIOUS

PDF

74.8 KB Created: 2021-09-11 20:19:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 970a30fdc91d98b61b73f4295f6c8be3 SHA-1: c444beecf5556725ea9f33393f427480a6caac7e SHA-256: 92539a9635bd83bcbea9c79d92554545e72320b67b0ae3b31cb989efd4e397de
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as a malicious PDF by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to PDF files on various domains, suggesting a link farm or redirection mechanism. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating the PDF is used to link to disposable hosting. While no scripts were explicitly extracted, the nature of the embedded URLs and the 'link farm' heuristic suggest the PDF's primary function is to redirect users to potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://newcar-rental.com/uploads/files/202109030959308580.pdf In PDF document text
    • http://clingac.com/d/files/49090073118.pdfIn PDF document text
    • http://kingkady.cn/uploadfile/files/gusap.pdfIn PDF document text
    • https://betalinktech.com/blmedia/file/tadojedakizi.pdfIn PDF document text
    • http://skinct.com/upload_file/file/Fl202109050318095665.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161393e7656dd4---bovativev.pdfIn PDF document text
    • http://apart1day.ru/file/terilijasarupitofojoj.pdfIn PDF document text
    • http://tchid.net/userfiles/file/89038186163.pdfIn PDF document text
    • http://samtekelektrik.com/files/porafutipuminirurisojuri.pdfIn PDF document text
    • http://asacnfservices.com/ckfinder/userfiles/files/buxeju.pdfIn PDF document text
    • http://dabaizhongxue.com/upload_fck/file/2021-9-9/20210909210836150997.pdfIn PDF document text
    • http://raylutickenterprises.com/userfiles/files/71756372794.pdfIn PDF document text
    • http://nujhimachal.in/img/uploads/files/xiben.pdfIn PDF document text
    • https://noelex22.org/userfiles/file/40513311407.pdfIn PDF document text
    • https://www.autopsrus.com/ckfinder/userfiles/files/96174494073.pdfIn PDF document text
    • http://aeklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/kajemax.pdfIn PDF document text
    • http://akademibt.com/resimler/files/dukarebi.pdfIn PDF document text
    • http://agrostroi-proekt.ru/ckfinder/userfiles/files/mijinibakafasoxunitonoz.pdfIn PDF document text
    • http://unitekinfostructures.com/userfiles/file/38475347367.pdfIn PDF document text
    • https://www.elshandmadedesign.nl/ckfinder/userfiles/files/82763565255.pdfIn PDF document text
    • http://tacchigroup.com/public/thread/risorse/file/vifawib.pdfIn PDF document text
    • https://greenturtleproductions.com.au/wp-content/plugins/super-forms/uploads/php/files/0d660d11a88a3721aa136b60d9ddadd0/wezudavawigufoxenet.pdfIn PDF document text
    • https://manenshop.com/upload/files/88685175890.pdfIn PDF document text
    • https://tybistanbul.org/resimler/files/15125384444.pdfIn PDF document text
    • http://directopinion.biz/uploads/FCK_files/file/luzinopuxesibomifu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=gta+vice+city+cheater+for+androidPDF 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_off0000c2a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2A8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dabf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDABF 10580 bytes
SHA-256: 6e126d41bb4db128f0865940ffcce98dabf4a97742ec689660b89ecc1110e8b6
font_02_sfnt_off0000f2ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2ED 16492 bytes
SHA-256: 897ebc8b4c176b2533ef4b55e449ec2e70c69a19e475b397ad01dfb20b6c6907