Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf163a78c08dc779…

MALICIOUS

PDF

79.5 KB Created: 2021-09-19 00:13:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: d9c445f990e405439b98d25e6ce85518 SHA-1: bc75e7718b341db759cf75da480a6583b0da39ba SHA-256: cf163a78c08dc7794148b39f3522cf48eda2a0cae47d82e848fb64417109e78f
66 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged as malicious by an ML classifier and contains numerous external URLs, many of which are associated with link farms. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the document is designed to host many links on disposable domains, suggesting a tactic to obscure malicious destinations or engage in SEO abuse for traffic generation. While no scripts were explicitly extracted, the presence of embedded URLs and the link farm nature strongly suggest a malicious redirection or phishing attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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 https://allytemp.ru/uplcv?utm_term=pdf+to+jpg+apk+pro PDF link annotation
    • http://votejoedestefano.com/editorData/file/35423421727.pdfIn PDF document text
    • https://pre-www.bridge-academy.com/uploaded/ckeditor/files/43774823142.pdfIn PDF document text
    • https://n-vv.dk/userfiles/file/81528677900.pdfIn PDF document text
    • http://studiorinaldibedin.eu/userfiles/files/janusaveburob.pdfIn PDF document text
    • http://susasoft.com/upload/userfiles/files/xonusasako.pdfIn PDF document text
    • http://sictombbi.fr/ckfinder/userfiles/files/nagesege.pdfIn PDF document text
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16139938d21dda---bafemotag.pdfIn PDF document text
    • http://inannamsao.com/uploads/files/21140606972.pdfIn PDF document text
    • http://donauwell.at/userfiles/file/8373872317.pdfIn PDF document text
    • https://pbchistoryonline.org/uploads/file/90659076931.pdfIn PDF document text
    • http://altadirezione-consulting.it/userfiles/files/vesuvogupexiruwedewiwugu.pdfIn PDF document text
    • https://vietrocknet.org/app/webroot/img/files/77324641819.pdfIn PDF document text
    • http://npk-bypassdrr2.com/file_media/file_image/file/butebefepo.pdfIn PDF document text
    • https://www.clinicaepilepsia.cl/ckfinder/userfiles/files/99141547916.pdfIn PDF document text
    • http://faisaltowel.com/survey/userfiles/files/bexotepaba.pdfIn PDF document text
    • http://thsport.dk/ckfinder/userfiles/files/5587713664.pdfIn PDF document text
    • http://leebyunghun.org/new/upload/board/files/95011149885.pdfIn PDF document text
    • https://prestinieurope.com/userfiles/files/tibirowegikejorelomaj.pdfIn PDF document text
    • https://n95america.com/wp-content/plugins/super-forms/uploads/php/files/2dd300f34eedba2a7f37d0a36aed9789/jivaxifi.pdfIn PDF document text
    • http://studiosimonepantaleo.it/userfiles/files/pilikemum.pdfIn PDF document text
    • http://riccaassociati.eu/userfiles/files/12973370171.pdfIn PDF document text
    • https://kltccompany.com/ckfinder/userfiles/files/fujetolan.pdfIn PDF document text
    • https://greenlakepaint.com/ckfinder/userfiles/files/sonori.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_off0000d3ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3AD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ebbf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBBF 17276 bytes
SHA-256: 6832034b986b7ef8b821f7bc253bf40d2c71a8cf970088be196ac44c4a28bf2f
font_02_sfnt_off000118e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118E8 10352 bytes
SHA-256: c21d7907fda416463dc2452af0d80b120db15905784dd02b8744c4bccf8c9cb5