Malicious PDF — malware analysis report

Static analysis result for SHA-256 51ab3f5f5aaae60f…

MALICIOUS

PDF

83.3 KB Created: 2021-09-16 11:50:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 7f4258992f250b2bc0555fd150a187a7 SHA-1: adf96bc6049013b7da28a437bd658c356c0b97c5 SHA-256: 51ab3f5f5aaae60f2f1e02727983ce95e3aa9b6e70ab1ca823df596c7a4673bd
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by ClamAV as Pdf.Phishing.Trojan and ML classifiers indicated a high probability of maliciousness. The PDF contains numerous embedded URLs, many of which are hosted on disposable domains or are part of a link farm, suggesting a phishing or redirection scheme. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly indicate it's designed to lead users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://ecohouse-lab.de/userfiles/file/4189377058.pdf In PDF document text
    • http://wiskind.com/filespath/files/20210908031616.pdfIn PDF document text
    • https://shieldtech.cz/ckfinder/userfiles/files/zukininibodexomadegaguxip.pdfIn PDF document text
    • http://hjhchem.com/upload/files/telibanazewavadu.pdfIn PDF document text
    • https://pacientes.quiroser.com/UserFilesQUI/file/wanumuv.pdfIn PDF document text
    • http://nepodoshlo.kz/ckfinder/userfiles/files/tulaluwunidonimitoramu.pdfIn PDF document text
    • http://lavalnerina.it/userfiles/file/34037182336.pdfIn PDF document text
    • http://nataliashishkina.com/userfiles/file/naderofasevobevutebowa.pdfIn PDF document text
    • https://hbphoto.ca/resimler/files/zofonevulofozubuxa.pdfIn PDF document text
    • https://legend-chang.com/UserFiles/files/zemolejejuguwavas.pdfIn PDF document text
    • http://open.ua/uploads/ckeditor/files/88215440811.pdfIn PDF document text
    • http://wxdyzs.com/userfiles/files/82977429865.pdfIn PDF document text
    • http://ncteonline.com/userfiles/file/jemifalusobuwutug.pdfIn PDF document text
    • https://www.bocamvigliesrooms.com/wp-content/plugins/super-forms/uploads/php/files/9ebd2ce8e5e79d8b4b84de545d375203/26244576029.pdfIn PDF document text
    • https://itracmediav5.com/ckfinder/userfiles/files/11946465780.pdfIn PDF document text
    • http://lagunarent.lt/ckfinder/userfiles/files/62738341542.pdfIn PDF document text
    • https://www.privathospitaletkollund.com/ckfinder/userfiles/files/48763920429.pdfIn PDF document text
    • http://safetyassessmentsolutions.co.uk/ckfinder/userfiles/files/47308215446.pdfIn PDF document text
    • http://elitk.ru/_files/lopozexezigeroz.pdfIn PDF document text
    • https://www.willmarshelter.com/ckfinder/userfiles/files/gukipifatuluwu.pdfIn PDF document text
    • http://acudrved.com/ckfinder/userfiles/files/17789160504.pdfIn PDF document text
    • https://1877painters.com/FCKeditor/file/81570475202.pdfIn PDF document text
    • https://www.marjojaspers.nl/ckfinder/userfiles/files/25648685656.pdfIn PDF document text
    • http://thewesternmist.com/userfiles/file/gexegamipizuwilinibumito.pdfIn PDF document text
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613db1ef4db87---fenonanejilup.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=should+i+clear+data+on+android+appsPDF 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_off0000e21e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE21E 17084 bytes
SHA-256: 0b950271d9ca6e91c83ede5673171b6d00c01a36b60a70ee10d84ed444f889b8
font_01_sfnt_off00010e49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E49 10784 bytes
SHA-256: 6707222c688c86f4b6cb9eb387c8118c11b91a9dc82367d59abe6dfbfa0706b2
font_02_sfnt_off00012707.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12707 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1