Malicious PDF — malware analysis report

Static analysis result for SHA-256 8dad399464035556…

MALICIOUS

PDF

81.1 KB Created: 2021-09-08 15:14:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 1099f906e278d04ab82797824985068a SHA-1: 10af64a3d8352a6db0ed3b2421b08cc95eb1d6fd SHA-256: 8dad399464035556dfe09653529db17c6e1d709d4a85a53c93f2a446901a17ab
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, with high confidence. It contains embedded JavaScript which is likely responsible for redirecting the user to a link farm, as indicated by the PDF_SEO_DISPOSABLE_LINK_FARM heuristic and the numerous extracted URLs. The primary purpose appears to be phishing or distributing further malware through these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://www.ishvani.com/www/js/ckfinder/userfiles/files/26058328809.pdf In PDF document text
    • https://www.gryf-wet.pl/ckfinder/userfiles/files/24849490621.pdfIn PDF document text
    • http://dulwichtaxi.com/survey/userfiles/files/39070233210.pdfIn PDF document text
    • http://hamkr.com/userData/board/file/vewosebidizonijabosugabu.pdfIn PDF document text
    • http://ryanoomen.nl/uploadimages/files/xuvisogofiwejusexom.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/16133252e1f326---82578347454.pdfIn PDF document text
    • http://parbatsamajjapan.com/img/files/files/molawikojatudifaxipib.pdfIn PDF document text
    • http://raegcafe.com/uploads/files/zazikagonumevewuxub.pdfIn PDF document text
    • https://dutchfansitenetwork.nl/ckfinder/userfiles/files/66871333613.pdfIn PDF document text
    • http://slkuang.com/v15/Upload/file/202195195698369.pdfIn PDF document text
    • http://ampletrekking.com/userfiles/file/6494135693.pdfIn PDF document text
    • http://clinicaveterinariagussago.com/userfiles/files/kodopaxiwuv.pdfIn PDF document text
    • http://studiosimonepantaleo.it/userfiles/files/34554205747.pdfIn PDF document text
    • http://carnow.jp/js/upload/files/jodukiwibemol.pdfIn PDF document text
    • https://perfecthospitals.org/FCKeditor/file/14757769376.pdfIn PDF document text
    • http://kawana.tech/userfiles/file/24790675312.pdfIn PDF document text
    • http://popmetre.com/news/files/xuderewuresadutiruboj.pdfIn PDF document text
    • http://iburgisidimarsala.eu/userfiles/files/tasopuxazisoxano.pdfIn PDF document text
    • http://henca.com/files/details/file/95851483203.pdfIn PDF document text
    • https://www.alongsideasia.com/wp-content/plugins/super-forms/uploads/php/files/9b5d221ac753c6471ce87c8d2781d3ef/82983623364.pdfIn PDF document text
    • http://ulleungroadtour.com/FileData/ckfinder/files/20210904_CA18BA03051B34E7.pdfIn PDF document text
    • https://1tlstar.com/storage/uploads/files/jedakonixakobigovokazo.pdfIn PDF document text
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1612f1ffee919a---56338647356.pdfIn PDF document text
    • http://chhattisgarhsanskritboard.in/sharpinstitute/images/files/62840344521.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=english+grammar+tense+exercises+pdfPDF 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_off0000d73b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD73B 11032 bytes
SHA-256: d5a8258389cc4f3259a15f9c774abf7ee24b2655e61ec3a8c5f0c60e99f10ee9
font_01_sfnt_off0000f076.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF076 17752 bytes
SHA-256: 57a61f1f5caa08498ace52630159e36182cb030936e6c1301498625384b4953d
font_02_sfnt_off00011e95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E95 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1