Malicious PDF — malware analysis report

Static analysis result for SHA-256 915b9f7ef5fb6a55…

MALICIOUS

PDF

79.1 KB Created: 2021-09-22 13:36:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: ed381386611ef00040a8acea07433b9c SHA-1: f1c62d1d3e2e737c6e013a0831b4b91a127d4daf SHA-256: 915b9f7ef5fb6a555187f7bb79d33006b651e0892e2f60fa8f8942d3e95a07b5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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 farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://lumieye.com/userData/ebizro_board/file/10882830190.pdf In PDF document text
    • https://laetitiabernard.fr/images/file/3105033964.pdfIn PDF document text
    • https://jeanmarcrobion.fr/userfiles/file/60173068997.pdfIn PDF document text
    • http://gima.ge/admin/ckeditor/ckfinder/userfiles/files/6534326779.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161369f60cb629---sasorurutuwew.pdfIn PDF document text
    • http://associatedreclaimed.com/userfiles/files/fedukogojokukekomabameler.pdfIn PDF document text
    • http://kursadowicz.pl/Upload/file/bapidogap.pdfIn PDF document text
    • http://www.mariabeckmann.com/fotos/uploads/files/lurimevinozasop.pdfIn PDF document text
    • http://nail-free.com/ckfinder/userfiles/files/26735286367.pdfIn PDF document text
    • http://www.detskaoptika.cz/ckfinder/userfiles/files/gaper.pdfIn PDF document text
    • http://oembag.com/uploads/files/202109041811386438.pdfIn PDF document text
    • http://bettynblue.com/upload/fck_img/20210909/file/wibegetumik.pdfIn PDF document text
    • http://ozkayalarlojistik.com/userfiles/file/45672794754.pdfIn PDF document text
    • http://coimbrasoftware.hu/images/uploads/files/88564616039.pdfIn PDF document text
    • http://siciny.pl/userfiles/file/892983995.pdfIn PDF document text
    • http://miroslaws.com/ckfinder/userfiles/files/biduvizaluruganed.pdfIn PDF document text
    • http://ogcdc.org/uploads/ck_upload/files/63966446312.pdfIn PDF document text
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/161408b181687d---tumewawafiguzonukimipusa.pdfIn PDF document text
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/632b85ae83831694900a09da8393fa95/pifamaretaw.pdfIn PDF document text
    • https://steklo-shik.ru/userfiles/file/jesemomamaxibuwubisixiwu.pdfIn PDF document text
    • http://mulroyenvironmental.ie/userfiles/file/vedobikilolujox.pdfIn PDF document text
    • https://fruitssupplier.com/app/webroot/img/files/tizinada.pdfIn PDF document text
    • https://drrajanmahtani.com/userfiles/files/94881436384.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=android+keyboard+voice+to+textPDF 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_off0000cfbe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFBE 10644 bytes
SHA-256: dc494bf87a39d413b9cbd06a805942281a52cd68d8df35148bb9bbbf02b9328e
font_01_sfnt_off0000e84a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE84A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001005c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1005C 18060 bytes
SHA-256: 809dae53f48235e3e7423c4363c9a57cb16508e871b56fe6f454ac05e4c5c43e