Malicious PDF — malware analysis report

Static analysis result for SHA-256 ec4665a871f6fff5…

MALICIOUS

PDF

77.6 KB Created: 2021-09-23 04:06:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 3fbbe64ca9217bdefd8ef169a08d9778 SHA-1: f70b49c9532d8538d429e691f8084a8b8d996e17 SHA-256: ec4665a871f6fff53bd5ef09df242599b848bf986cb39e94cdac361d823421ce
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of external links, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://tks-forever.com/upload/2021/09/05/file/92875806010.pdf In PDF document text
    • http://seanbittinger.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/60380252988.pdfIn PDF document text
    • https://sushixusa.com/userfiles/files/89288050820.pdfIn PDF document text
    • http://benthanhsgfarm.com/images/uploads/files/19638477933.pdfIn PDF document text
    • https://aymfly.com/aym_image/files/85333014511.pdfIn PDF document text
    • http://sportingclubalbinia.eu/userfiles/files/74700404532.pdfIn PDF document text
    • http://studiotrusso.it/userfiles/files/36101478224.pdfIn PDF document text
    • https://groupunsur3.com/contents/files/dimubepenerebexome.pdfIn PDF document text
    • http://beerskiboot.com/img/upload/file/wopusizos.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/16133b7f4cc644---verir.pdfIn PDF document text
    • http://www.videobezopasnost.ru/ckfinder/userfiles/files/xudugesa.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/ka56c4tj3bhi2g3um1hnvpbt6l/61426255539.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/161462e54adf96.pdfIn PDF document text
    • http://jingkangchem.com/upload/files/zopasilixam.pdfIn PDF document text
    • https://trexanh.net/upload/files/xexasefevalodigavameg.pdfIn PDF document text
    • http://goksirlambinowice.pl/img/upload/files/75224417598.pdfIn PDF document text
    • http://gardatrans.com/content/Files/xibofibeputumisosir.pdfIn PDF document text
    • https://citronel.com/userfiles/files/temezifekazufogawoxud.pdfIn PDF document text
    • http://dagmar-e.de/userfiles/file/4544043644.pdfIn PDF document text
    • https://mgc.to/sites/web/upload/files/28194772585.pdfIn PDF document text
    • https://www.renouer-auxerre.com/ckfinder/userfiles/files/bekekomejufugexigonuwu.pdfIn PDF document text
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161410edf7f48b---13413594621.pdfIn PDF document text
    • http://aibasavar.edu.bd/app/webroot/ckfinder/userfiles/files/firidawuwez.pdfIn PDF document text
    • http://palakkadtourism.in/ckfinder/userfiles/files/10373956110.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=kof+97+hd+apkPDF 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_off0000c7d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7D5 10156 bytes
SHA-256: 6ee223c9bb50ed3fa737d0c61106b1cdc0edafd5b5790514233a20950af8c17d
font_01_sfnt_off0000debe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEBE 18996 bytes
SHA-256: 482f47939878702c0dbfb4df8aa64b5e9503b067289e32277bef118f7a588a27
font_02_sfnt_off000110e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110E1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1