Malicious PDF — malware analysis report

Static analysis result for SHA-256 51300854e8bfa6b3…

MALICIOUS

PDF

72.0 KB Created: 2021-09-19 06:51:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: f9cee6ec0276f4873fbe9a9336646711 SHA-1: 8fcd84fde4227d23259139345dd0e732dfbcb9a7 SHA-256: 51300854e8bfa6b34f8a61a9d39dc3fcca77ffd1ef2aa92dad6b1c246ddbc116
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains a large number of embedded URLs, many of which point to disposable hosting and are structured as link farms, suggesting a phishing or malware distribution campaign. While no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9979

Heuristics 5

  • 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.
  • 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://ketchas.ru/uplcv?utm_term=vocabulary+workshop+level+blue+answer+key+pdf PDF link annotation
    • http://tienphat.vn/imagesflashupload/file/tijokikoxi.pdfIn PDF document text
    • https://booking-news.hkdnracing.com/webroot/editor-uploads/files/59809746972.pdfIn PDF document text
    • http://oldmotorsclub.com/files/file/jedeniperasimivif.pdfIn PDF document text
    • http://marketingnews.fr/images/file/10053525869.pdfIn PDF document text
    • http://abbuffalowings.com/uploads/files/85886716797.pdfIn PDF document text
    • http://bdpq.hungminhits.com/files/uploaded/files/tekefavuw.pdfIn PDF document text
    • https://ville-saintleonard.fr/pdf/tinal.pdfIn PDF document text
    • http://music-saikung.com/ckfinder/userfiles/files/36378870752.pdfIn PDF document text
    • https://noriupapildu.lt/ckfinder/userfiles/files/mikoxalutux.pdfIn PDF document text
    • http://www.centrosanmarco.eu/img/news/files/4531226158.pdfIn PDF document text
    • http://www.rosabrockenhaus.ch/ckfinder/userfiles/files/tunikexetemelifedezap.pdfIn PDF document text
    • https://istanajpdua.com/contents/files/ralef.pdfIn PDF document text
    • http://atlonnuri.org/UpLoadImage/editer/files/62061081257.pdfIn PDF document text
    • http://yidaig.com/uploadfile/file/20210912185442.pdfIn PDF document text
    • http://xn--90aoj0agf7cq.xn--p1ai/uploads/files/fewoziguzavezudevidare.pdfIn PDF document text
    • http://yztools.com/images/upload/File/58932779278.pdfIn PDF document text
    • https://freebcard.com/ckfinder/userfiles/files/4399887950.pdfIn PDF document text
    • http://architettoannalisatinelli.it/userfiles/files/fexejen.pdfIn PDF document text
    • http://www.phuongdonggolf.vn/app/webroot/uploads/files/9267458805.pdfIn PDF document text
    • https://chungangroup.com/uploads/files/202109131723058357.pdfIn PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/161436b9aeb3f4---bumoputagelaxi.pdfIn PDF document text
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/2a846741e9831ea76f7134757b47711d/25765914254.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_off0000b7d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB7D1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cfe8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFE8 11092 bytes
SHA-256: a073a241603cc71732e35f166bc3ec0f72ac3c01a17a619cbfaab0c8fd8e4561
font_02_sfnt_off0000e998.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE998 15780 bytes
SHA-256: d8f4da19aaa4509a11722994cd5bad2dee18061f926547c503d4009d4a8974e9