Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4306163bde3adf5…

MALICIOUS

PDF

70.1 KB Created: 2021-09-16 07:09:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: e7c639c7f326182434574dcceac1c991 SHA-1: 16853a5eedef2618693222697cce5cab08cccb6c SHA-256: c4306163bde3adf511e0b5c16c21b1690779447fbb37979b4ed59f7475ec4e22
134 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The sample was flagged by ML classifiers and ClamAV as malicious, with critical and high severity heuristic firings indicating embedded JavaScript and external URIs. The PDF structure suggests it's a link farm designed to redirect users to potentially malicious content, as indicated by the PDF_SEO_DISPOSABLE_LINK_FARM heuristic. The embedded JavaScript is likely used to facilitate the redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • 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.
  • 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://baohanhranghm.com/upload/img/files/74827113042.pdf In PDF document text
    • http://ng-sons.com/userfiles/file/tawuwudugagikeju.pdfIn PDF document text
    • http://studiosantomauro.it/userfiles/files/xolije.pdfIn PDF document text
    • http://gocoachfox.com/userfiles/file/90656955192.pdfIn PDF document text
    • http://9jamail.com/FCKeditor/editor/filemanager/connectors/userfiles/file/11700416663.pdfIn PDF document text
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142bb457d67e---lorevojugajas.pdfIn PDF document text
    • https://textosolutionslinguistiques.com/upload/editor/file/kujoluvo.pdfIn PDF document text
    • http://edumedcare.pl/upload/files/minumojedib.pdfIn PDF document text
    • https://jeevandeepspecialcare.com/ckeditor/ckfinder/userfiles/files/masunagofivu.pdfIn PDF document text
    • https://houstoncoinclub.org/FCKeditor/file/66751295482.pdfIn PDF document text
    • http://kurumakaitori-one.com/js/upload/files/57159476106.pdfIn PDF document text
    • http://asdgolfclubtoscana.com/writable/public/userfiles/file/7244819187.pdfIn PDF document text
    • https://sergiomauri.com/images/file/89474038861.pdfIn PDF document text
    • http://sntaviator.ru/ckfinder/userfiles/files/7525216418.pdfIn PDF document text
    • https://npkfertilizerproduction.com/d/files/31092343561.pdfIn PDF document text
    • http://weiken-rc.com/upload/files/28047560875.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1613793a92dc72---67601503838.pdfIn PDF document text
    • http://educaholistica.com/resources/img/imagesck/files/50644869183.pdfIn PDF document text
    • https://afra24.com/basefile/afra24/files/62478812353.pdfIn PDF document text
    • https://economiadecomunion.com/ckfinder/userfiles/files/37097683779.pdfIn PDF document text
    • http://baigeleather.com/userfiles/file/wevovunuridadodedunugap.pdfIn PDF document text
    • http://xingzhongjing.com/userfiles/file/20210907062808_1299621685.pdfIn PDF document text
    • http://dtmaso.com/public_html/Imagens/file/27411973287.pdfIn PDF document text
    • http://prmakeup.com/Image/files/wevazi.pdfIn PDF document text
    • http://vikohasanfiber.com/upload/files/95384505807.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=wolverine+game+download+for+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_off0000b433.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB433 15184 bytes
SHA-256: ba569bd9c2e72c5f47b4e5ed624d13c534b2e68589ff68ea36973d26103caafc
font_01_sfnt_off0000da7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA7A 10576 bytes
SHA-256: e20bf98cdbebb075bb43868cd89f49c9b7ae728e99ad877b956c0cede4d6094e
font_02_sfnt_off0000f26a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF26A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1