Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3f0a312280a55e1…

MALICIOUS

PDF

74.6 KB Created: 2021-09-18 14:22:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 19dfdf95754a3173769fc516b61b296c SHA-1: 903ea9387a56454dcb30c7e8fb28873167704ecc SHA-256: a3f0a312280a55e1b9b330cd45386fbf760b2a761182a8ac57e4ae715a7a5b28
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to a link farm hosted on disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded JavaScript likely facilitates the redirection to these external links, which are designed to appear as legitimate files but serve a malicious purpose, such as SEO manipulation or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://uniontsg96.ru/admin/ckfinder/userfiles/files/72213177902.pdf In PDF document text
    • http://perechen-izdaniy.ru/js/ckfinder/userfiles/files/31170448398.pdfIn PDF document text
    • http://nieruchomosciklodzko.pl/files/file/jelumuzoxosokirobiwux.pdfIn PDF document text
    • http://irinaburmistrova.ru/files/zitokixidowubowibiku.pdfIn PDF document text
    • https://perfecthospital.org/FCKeditor/file/vikeruzamujewizunakad.pdfIn PDF document text
    • https://nvsrolko.org/ckfinder/userfiles/files/93979970592.pdfIn PDF document text
    • https://enerjimakine.com/tsrm1/img/userfiles/file/69156604931.pdfIn PDF document text
    • https://vozilasavozacem.rs/files/90707708773.pdfIn PDF document text
    • http://stroykap.com/application/views/stroykap/userfiles/file/59419123040.pdfIn PDF document text
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/16132ca64868f4---lamegofifedabube.pdfIn PDF document text
    • http://hophungvietnam.com/app/webroot/uploads/files/pifotojowud.pdfIn PDF document text
    • http://ajtoablakcentrum.com/_user/file/lugixarawatimijaxorafi.pdfIn PDF document text
    • http://cissi.it/userfiles/files/76540015036.pdfIn PDF document text
    • http://studiolegalebisantis.it/userfiles/files/96575031147.pdfIn PDF document text
    • http://xlsferrosilicon.com/d/files/38710735178.pdfIn PDF document text
    • http://skonasystems.com/userfiles/file/kegonefudorusew.pdfIn PDF document text
    • http://naturallabs.fr/userfiles/file/75520956180.pdfIn PDF document text
    • https://quatden.vn/webroot/img/files/35154393216.pdfIn PDF document text
    • http://pk-rowery.pl/user_pict/file/11316986333.pdfIn PDF document text
    • http://malifer.hu/upload/file/jobage.pdfIn PDF document text
    • http://huyndaicaudien.com/upload/files/tidewesotuwud.pdfIn PDF document text
    • http://madiagranitosilano.it/userfiles/files/42419432048.pdfIn PDF document text
    • https://sunarchegypt.com/userfiles/file/jebofazefesorarutavix.pdfIn PDF document text
    • http://offerparts.com/upload/files/sonawilufuwuvodadav.pdfIn PDF document text
    • http://dalnoboy.org/data/filestorage/upload/files/5493968138.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=how+to+find+deleted+photos+in+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_off0000be3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE3D 18108 bytes
SHA-256: 417de79dad6161bc0b3802af2761ca8f9ac1cf32174cca622cdf9cf5c9f9e5b4
font_01_sfnt_off0000ec96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC96 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000104ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104AD 10672 bytes
SHA-256: 8bfc51d628628a65c82c8479bec1d05fb613a2aaee4e361a51f6279098e94e4e