Malicious PDF — malware analysis report

Static analysis result for SHA-256 b683789f6b43361c…

MALICIOUS

PDF

79.3 KB Created: 2021-09-18 06:11:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 115f997f37f1976203450ade805261f7 SHA-1: b922bc62371e84c8877b4a93a50213a42975e00d SHA-256: b683789f6b43361ce7cfe52d308585e9d7e897530142441887386e903474e5eb
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to numerous other PDF files hosted on disposable domains. While no scripts were directly extracted, the PDF structure and the presence of external links suggest an attempt to redirect users to malicious content, potentially for phishing or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://uptownchantilly.com/uploads/files/jiturovumezutotogofi.pdf In PDF document text
    • http://cutyoursupport.com/userfiles/file/37708614420.pdfIn PDF document text
    • http://ty6600.com/userfiles/file/64362198234.pdfIn PDF document text
    • https://alhurwallpaper.com/Files/files/buvulakisuvupixevu.pdfIn PDF document text
    • http://top-caster.com/userfiles/file/20189594758.pdfIn PDF document text
    • https://trimix.bg/UserFiles/File/xewiboxiva.pdfIn PDF document text
    • https://iagclaims.endataclaims.com/ModCoreFilesUploaded/file/radasitimiviwitefoni.pdfIn PDF document text
    • http://www.cda.org.hk/ckfinder/userfiles/files/getovejaseg.pdfIn PDF document text
    • https://www.almuhja.com/ckfinder/userfiles/files/83757475799.pdfIn PDF document text
    • https://sieuthimaytinhcu.vn/upload/files/39751259938.pdfIn PDF document text
    • https://kfk-dekoration.dk/images/uploadedimages/file/74853002248.pdfIn PDF document text
    • http://www.feniuniversity.edu.bd/app/webroot/ckfinder/userfiles/files/9531422867.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/f076d12a94d6b33567aa644c49693ec3/3761551642.pdfIn PDF document text
    • http://hotstamping.pl/files/file/pewub.pdfIn PDF document text
    • https://zagorjeadventureteam.hr/files/48838162782.pdfIn PDF document text
    • http://saddabro.com/userfiles/file/11337484894.pdfIn PDF document text
    • http://dgjst.com/upfile/file/36893703370.pdfIn PDF document text
    • http://sportsclinicwest.ie/media/contents/file/bekofufavototodun.pdfIn PDF document text
    • http://anpo.vn/upload/files/57083338092.pdfIn PDF document text
    • http://jmk.kr/ckfinder/userfiles/files/9643511094.pdfIn PDF document text
    • http://mama-care.com/UserFiles/file/78290282351.pdfIn PDF document text
    • http://ampletrekking.com/userfiles/file/pated.pdfIn PDF document text
    • http://recrute.fr/files/files/negapefi.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/16144fe9a5c57c---25406253055.pdfIn PDF document text
    • http://52963566.com/upload/file/202109030704061798.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=how+to+remove+messenger+from+instagramPDF 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_off0000cedc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEDC 18248 bytes
SHA-256: 29173d383c2a4c2d84bb5ad32f7252bb0597a7e615d0031e5425bb2dacafd0a6
font_01_sfnt_off0000fe9c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE9C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000116b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116B3 10656 bytes
SHA-256: aac8c606ec375781b81bb63d9de96d424d289ce76164f7ae5a9e5845a84e88ed