Malicious PDF — malware analysis report

Static analysis result for SHA-256 438533027ec76a08…

MALICIOUS

PDF

81.9 KB Created: 2021-09-23 08:58:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 25ebbff303f839e8b86cf6af4d51d0e2 SHA-1: 8b184150a2734dbf0b47fad78f02ccf62754eea8 SHA-256: 438533027ec76a082765a7d30b78071e5a28c802b280efe59edda1a1caa5fc20
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by multiple heuristics, including ML classification and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous external URIs and is structured as a link farm, suggesting it's designed to redirect users to potentially harmful websites. Although no scripts were explicitly extracted, the presence of external links and the 'ML_NYX_PDF_MALICIOUS' heuristic suggest it may leverage embedded JavaScript or other exploits to achieve its objective.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • 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.
  • 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://krisoc.ru/uplcv?utm_term=download+video+for+instagram+apk PDF link annotation
    • http://preciz.com/uploads/wysiwyg/files/jujoxulewu.pdfIn PDF document text
    • http://worldplastsolution.com/ckfinder/userfiles/files/56747716111.pdfIn PDF document text
    • http://candleelectricals.com/uploaded_files/userfiles/files/jofepetatodubed.pdfIn PDF document text
    • http://electriccityusa.com/images/fck_uploads/file/morezazosozudujosefosixa.pdfIn PDF document text
    • http://soles2walk.com/data/file/sogawemupedefemilow.pdfIn PDF document text
    • http://rld-carbon.com/file/8580124296.pdfIn PDF document text
    • http://iccj.jp/images/uploads/fckeditor/file/36680843971.pdfIn PDF document text
    • https://svenjakretschmer.com/ckfinder/userfiles/files/72381841766.pdfIn PDF document text
    • http://ncteonline.com/userfiles/file/3504382546.pdfIn PDF document text
    • https://daulte.ch/ckfinder/userfiles/files/deguniz.pdfIn PDF document text
    • http://oembag.com/uploads/files/202109210946469733.pdfIn PDF document text
    • http://multiseal.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/161314413051f9---97642019360.pdfIn PDF document text
    • http://csc0898.com/userfiles/file/20210903032345_z27uu3.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/3b6e0129769f6df274947bba50f40e99/wimezisokajubof.pdfIn PDF document text
    • https://khabul.mn/mmpa/userfiles/files/7020735467.pdfIn PDF document text
    • http://stagelight.pl/userfiles/files/jiveregodawarobubuno.pdfIn PDF document text
    • https://canoe.ro/Extras/ckfinder/userfiles/files/56016301538.pdfIn PDF document text
    • https://mimpidia.com/contents/files/fevanezivupek.pdfIn PDF document text
    • http://e-skala.pl/userfiles/file/morelamuj.pdfIn PDF document text
    • https://free-spirit-city.eu/uploads/wysiwyg/files/74140061663.pdfIn PDF document text
    • http://tranhdaquydep.vn/upload/files/viwuzidoxo.pdfIn PDF document text
    • https://www.loisirs-auto-occasion.fr/ckfinder/userfiles/files/57384083023.pdfIn PDF document text
    • https://ochronaskory.pl/pliki_user/File/bapejija.pdfIn PDF document text
    • https://www.auto-ecole-rive-droite.fr/ckfinder/userfiles/files/28255095762.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_off0000db20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB20 17524 bytes
SHA-256: 423149c7bd27e342d09d1a584535fd599c5505497556637a9e21cc78c46a2d32
font_01_sfnt_off000107ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107EE 11088 bytes
SHA-256: 819ae107518c4526e84750210b6a81c4b6056a4860910e5568a7c2ab0039b649
font_02_sfnt_off0001219e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1219E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1