Malicious PDF — malware analysis report

Static analysis result for SHA-256 73530fbc973389bb…

MALICIOUS

PDF

92.0 KB Created: 2021-09-12 01:25:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: a2f710f8ad6d27e9940718d446295901 SHA-1: 5ebdd7d207cdbacabcdf433e8427bdb4de18ebb9 SHA-256: 73530fbc973389bb03d2c710e7e689001ac207c9c62298e9502b61d286d8cd0a
66 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, with a high heuristic firing indicating it functions as a link farm on disposable hosting. The ML classifier also flagged this PDF as malicious. While no scripts were explicitly extracted, the nature of the embedded URLs suggests a malicious redirection or phishing attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

Heuristics 4

  • 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://a899.net/userfiles/file/wepiderin.pdf In PDF document text
    • http://anhuizhkj.com/upload_fck/file/2021-9-12/20210912012511939086.pdfIn PDF document text
    • http://ettorebelfioreliutaio.it/userfiles/files/liruwitabipo.pdfIn PDF document text
    • https://veritiesinstitute.com/wp-content/plugins/super-forms/uploads/php/files/6df865e2348ecafd2cc1ee6b63e3408e/gikilesosor.pdfIn PDF document text
    • http://5thaveseniors.org/userfiles/file/5848558315.pdfIn PDF document text
    • http://cl-pub.com/files/files/3911259749.pdfIn PDF document text
    • http://veganogle.es/uploads/ckfinder/files/10465939468.pdfIn PDF document text
    • https://jpjplumbingandheating.com/FCKeditor/file/nubuduwonotasipusevula.pdfIn PDF document text
    • http://ubytovna-krumlov.cz/userfiles/file/jixinasagidasivarik.pdfIn PDF document text
    • http://sallytour.com/FileData/ckfinder/files/20210902_482BD7C116E68219.pdfIn PDF document text
    • https://mr-alian.com/upload/ckfinder/files/38989822968.pdfIn PDF document text
    • http://gandolfiarchitetti.com/userfiles/files/livuvudabenowoniwogej.pdfIn PDF document text
    • http://bibrka-school.org.ua/ckfinder/userfiles/files/dizulifirunodil.pdfIn PDF document text
    • http://royalgoodviewresort.com/Uploads/file/31096515702.pdfIn PDF document text
    • https://net-mex.hu/ckfinder/userfiles/files/30655854526.pdfIn PDF document text
    • https://equipelec.fr/ckfinder/userfiles/files/petojefo.pdfIn PDF document text
    • https://ln80.cn/filespath/files/20210904191523.pdfIn PDF document text
    • http://sandsflooring.co.uk/ckfinder/userfiles/files/toxedaxom.pdfIn PDF document text
    • https://givemeit.ru/wp-content/plugins/super-forms/uploads/php/files/28fca46733c77052220509b832707923/nakaveranasefax.pdfIn PDF document text
    • http://chenruichem.com/upload/files/14400631487.pdfIn PDF document text
    • http://kledingindex.nl/images/uploads/zikivalanewigebutipalamu.pdfIn PDF document text
    • http://cpghollywood.com/userfiles/files/67843530223.pdfIn PDF document text
    • https://coffotea.com/uploads/files/202109081317363337.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/16137a65013c24---sirado.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=us+full+movie+putlockerPDF 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_off000105c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105C9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011de0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DE0 10640 bytes
SHA-256: 01f217c84ba7172254a4e6d64d731744942d0830af35c8c0527af036d9cbfcf2
font_02_sfnt_off00013645.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13645 17228 bytes
SHA-256: 7eecfdf0ebfb6bdbdee490f5b7d3ee0b70575a6a016e6765f9a0af6243ddb967