Malicious PDF — malware analysis report

Static analysis result for SHA-256 fd67890d4ad5d372…

MALICIOUS

PDF

81.9 KB Created: 2021-09-20 18:50:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2c9facbbf879d68a6e970dc753a194df SHA-1: d55a1895a12c46e441c99efe0311a81c057405a7 SHA-256: fd67890d4ad5d372d395beaf1697c92fc9651fa582437b49e86802c63c735077
196 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many of which point to compromised CMS uploads and disposable hosting domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The presence of multiple PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics confirms the nature of the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 7

  • 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.
  • 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 https://ht-cooling-j3t.com/contents/files/25688858982.pdf
    • https://novamakine.com/upload/ckfinder/files/paboxidif.pdf
    • http://spreewaldpension-luebben.de/meineBilderAlbertGrundschule/file/1590888033.pdf
    • http://wellogo.in/userfiles/file///12058107643.pdf
    • https://abhrian.com/userfiles/files/82721412417.pdf
    • https://xnkvinatimex.com/uploads/files/domojujigikemifinat.pdf
    • http://secureyun.cn/uploadfile/file///2021091309362876.pdf
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/61974c3c962d23a53c328d2b900a11b7/79171937626.pdf
    • http://www.dkmodels.net/ckfinder/userfiles/files/majagup.pdf
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/32d3780413e2f3af588cea24b42ded65/31400138442.pdf
    • http://kimhoatra.com/upload/fckimagesfile/retusijapurotatejotoz.pdf
    • http://capriololaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/81328440322.pdf
    • https://vanphongphampmc.com/upload/files/buzozupep.pdf
    • http://ballarioarchitetti.eu/userfiles/files/koruvupiko.pdf
    • http://ambulatorioveterinariobubiniregini.eu/userfiles/files/liverikedum.pdf
    • http://jar-ted.pl/file/94175820828.pdf
    • http://xn--80aaa1acmiejxr6d7fg.xn--p1ai/data/files/87254193392.pdf
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/1866e7246b88d797ec34984a66ed3c00/xokaxifozamigowufa.pdf
    • http://sgpeo.pl/users/file/seziw.pdf
    • http://alfavit.tv/userfiles/file/12054445101.pdf
    • http://nhagiatxanh.com/public/default/ckeditor/files/6417984431.pdf
    • https://www.naabelectric.com/userfiles/files/12958624574.pdf
    • https://interstudy.net/userfiles/file/13294300788.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=best+paid+play+store+apps
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dcba.bin
44c038b6b9b3d4fc34f5dcc59f35d7c6e9a870590745d006b43621c7642ec92c
pdf-font-stream PDF embedded font (sfnt) at offset 0xDCBA 17724 bytes
font_01_sfnt_off00010aae.bin
57ca31e39295ea044de8777350077f702767219d9f4f9aa9657e15110bfa0fc7
pdf-font-stream PDF embedded font (sfnt) at offset 0x10AAE 10448 bytes
font_02_sfnt_off00012291.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12291 16792 bytes