Malicious PDF — malware analysis report

Static analysis result for SHA-256 31cdcb7d391ad6f9…

MALICIOUS

PDF

68.4 KB Created: 2021-09-19 13:21:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 1225a3625441bd294949beb6e091ea1a SHA-1: 0891df4ba856075025e7f34e3f9fab920e01c1de SHA-256: 31cdcb7d391ad6f9cd1397502835372e5e5ad6189973c919b03266f4d38af76c
146 Risk Score

Malware Insights

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

The PDF is identified as an image-only lure, typical for phishing or malware distribution. It contains numerous external URIs pointing to disposable hosting, suggesting a link farm designed to obscure the ultimate destination. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to a malicious site for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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
  • Image-only document with action trigger (screenshot lure) medium PDF_IMAGE_LURE
    PDF has 1 image(s), only 0 text block(s), carries a click-outward action, and is only 68 KB — typical shape of a phishing lure where a full-page screenshot hides a clickable button that launches or submits to an attacker URL.
  • 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://garglob.ru/uplcv?utm_term=gta+5+online+play PDF link annotation
    • http://webcertain.net/contentupload/fckeditorUploads/organization_/file/40069640667.pdfIn PDF document text
    • http://ecohort.com/userfiles/files/xonaxagurujigazurimi.pdfIn PDF document text
    • http://machinesupplier.cn/data/product/file/2021911_94949_664.pdfIn PDF document text
    • http://donateagift.eu/userfiles/file/golurirarike.pdfIn PDF document text
    • http://lapenya.cat/imgjovesnaves/file/lasasiraxalis.pdfIn PDF document text
    • http://faizleathergloves.com/userfiles/files/24222916754.pdfIn PDF document text
    • http://vegman-kzn.com/ckfinder/userfiles/files/28605857616.pdfIn PDF document text
    • http://ieeepes-thailand.org/app/webroot/files/files/7984942991.pdfIn PDF document text
    • https://tjpapigroup3.com/contents/files/danoxavotibodijikapibat.pdfIn PDF document text
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/69fcad9c3f8828b155ba143cb981e382/87632235924.pdfIn PDF document text
    • http://eros-arena.de/eros/userfiles/file/8900156046.pdfIn PDF document text
    • https://purefeeling8.com/data/file/21796574409.pdfIn PDF document text
    • http://serviphony.com/tinymce/jscripts/tiny_mce/plugins/phpimage/phpimage/upload/images/file/51019794864.pdfIn PDF document text
    • https://obermeyer-modemarkt.de/upload/file/fosikaxikamodolodasuxetux.pdfIn PDF document text
    • http://amsaneeraus.fi/userfiles/files/xowunitemevosa.pdfIn PDF document text
    • https://ssekolkata.com/ckfinder/userfiles/files/bogavopavulofageworosa.pdfIn PDF document text
    • https://rubyyadav.com/nbloom/fckuploads/file/wejazuvujobedetejefawow.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f08eea05ab---siparasagokogujidupak.pdfIn PDF document text
    • https://betalinktech.com/blmedia/file/wogamo.pdfIn PDF document text
    • http://fairfresh.net/assets/admin/ckeditorimage/files/3767565525.pdfIn PDF document text
    • http://tradotel-riviera.com/file/xizijawovabu.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_off0000b1de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1DE 14020 bytes
SHA-256: 33405b9c6cdf4dfd2f7ededbf275e4ad886341366fad1aeed5754b83999e7e6c
font_01_sfnt_off0000d4cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4CD 10264 bytes
SHA-256: b0e72ea3317f57edd3f1cd43407f6542a3e277e9eb28836564a9b283dff138fa
font_02_sfnt_off0000ec14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC14 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1