Malicious PDF — malware analysis report

Static analysis result for SHA-256 509bb113ed0713fa…

MALICIOUS

PDF

80.2 KB Created: 2021-09-14 04:17:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: d90991be0b793eb734a0d6e449905113 SHA-1: 4454014d02cdc36205dbb219f6964d73b13c9cd1 SHA-256: 509bb113ed0713fa4d1726dad1e83885ecaceabc44425e526d04fadd225e1d60
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple external links, with one identified as an algorithmically-generated URL pointing to a suspicious PDF file. The 'ML_NYX_PDF_MALICIOUS' and 'CLAMAV_DETECTION' heuristics strongly indicate malicious intent. The presence of embedded URLs and the PDF structure suggest a phishing or malware distribution attempt, likely leveraging spearphishing as an initial access vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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 http://tokyosushilohaus.com/uploads/files/luzugoxalupik.pdf In PDF document text
    • http://marktoby.com/akram/know_news/admin/userfiles/file/84495519517.pdfIn PDF document text
    • http://drzwiukryte.pl/userfiles/file/xikuvu.pdfIn PDF document text
    • http://billagelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/91510848499.pdfIn PDF document text
    • http://kimwendelldesign.com/ckfinder/userfiles/files/30177914426.pdfIn PDF document text
    • https://aldwalia.com/userfiles/files/gezuxelijaki.pdfIn PDF document text
    • http://www.fan-consultants.com.tw/ezadmin/ckfinder/userfiles/files/26607275055.pdfIn PDF document text
    • http://focalthai.com/file_media/file_image/file/43212145002.pdfIn PDF document text
    • http://covina.crazyrockinsushi.com/uploads/files/68275620248.pdfIn PDF document text
    • http://uni-farm.pl/ckfinder/userfiles/files/50410409823.pdfIn PDF document text
    • http://santehnika34.ru/images/file/juxufi.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132406336027---makulafonasej.pdfIn PDF document text
    • http://thegioichuyendong.info/app/webroot/upload/files/51614783650.pdfIn PDF document text
    • http://aromata.ru/upload/files/11447865810.pdfIn PDF document text
    • http://master-sign.ru/ckfinder/userfiles/files/remefidodi.pdfIn PDF document text
    • https://stthomasorthodoxchurchsouthpampady.com/userfiles/file/43023091883.pdfIn PDF document text
    • http://zjhywt.com/images/upload/File/39141411750.pdfIn PDF document text
    • http://kangmeideyiliao.com/uploadfile/file///2021090507513754.pdfIn PDF document text
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/161316d4fe32a5---lotulasosig.pdfIn PDF document text
    • http://www.mousumibanerjee.com/fckimages/file/popiruvofazijusinovoj.pdfIn PDF document text
    • http://decom.pro/admin/ckfinder/userfiles/files/zumodanikigorajumo.pdfIn PDF document text
    • https://tradingphrases.net/userfiles/files/dezofozaxefagojijexemiwub.pdfIn PDF document text
    • https://pacie.vn/web/uploads/files/14531149850.pdfIn PDF document text
    • http://firmen-bekleidung.at/userfiles/file/9790395109.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=create+folder+shortcut+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_off0000d62f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD62F 10704 bytes
SHA-256: 08252456b6d350105e63924b7740c9ed9122547e014ecf98351d4d828bc1a7b2
font_01_sfnt_off0000eeb5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEB5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000106c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106C7 17104 bytes
SHA-256: 3d81615c35e6a10e1eaa6c245e53375dedb7607b1c656bd64cbebecafed1536e