Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b236fe66dc19ea5…

MALICIOUS

PDF

76.8 KB Created: 2021-09-09 12:18:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 778ac4d3e7b385c34568639ca999d5a5 SHA-1: cb0d596a0be684c1d1340c4cccd379eba25666ff SHA-256: 3b236fe66dc19ea5a8ad7a89b6669777b6d7b17ddd9d543a9a1c4080b1a8b559
156 Risk Score

Malware Insights

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

The file was detected as a malicious PDF by ClamAV and an ML classifier. It contains a link farm with multiple URLs pointing to PDF files hosted on various websites, some of which are identified as compromised CMS uploads. The primary purpose appears to be redirecting users to these hosted files, likely as part of a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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 https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/8e8f56efc3c7a16988abef1d05832319/tafisideguzaxomoxuwux.pdf In PDF document text
    • http://hzzxtl.com/UploadFile/file/20210903124813582.pdfIn PDF document text
    • http://burattinojatek.hu/userfiles/file/73581015954.pdfIn PDF document text
    • http://jandenzobv.com/image_uploads/file/19315250119.pdfIn PDF document text
    • http://koreanhotpot.com/uploads/files/pinixezufikurarugib.pdfIn PDF document text
    • https://ghnservizi.com/file/jigopanijokoredad.pdfIn PDF document text
    • http://idealhca.com/admin/images/file/vikozefavokilipar.pdfIn PDF document text
    • http://nhatrangpalace.net/app/webroot/upload/files/rewujexubumisu.pdfIn PDF document text
    • https://idroilektriki.gr/files/file/11786217106.pdfIn PDF document text
    • https://gppacdatabase.net/userfiles/file/9921902146.pdfIn PDF document text
    • https://tonmathunglan.vn/upload/files/rafubapekop.pdfIn PDF document text
    • https://polaria.cz/images/file/zutupofuzawasurebiloku.pdfIn PDF document text
    • http://piotrkowska77.pl/zdjeciafile/22487955239.pdfIn PDF document text
    • http://dylogistics.com/userData/board/file/22456183294.pdfIn PDF document text
    • http://www.jokilaaksonratsastajat.fi/file/87732874720.pdfIn PDF document text
    • http://atthaya.com/file_media/file_image/file/741175686.pdfIn PDF document text
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/161304ca42788f---bofepuzupogesed.pdfIn PDF document text
    • https://commonwealthsportsawards.com/userfiles/file/90983044419.pdfIn PDF document text
    • https://paperland.bg/uploads/file/gokezowixebubataw.pdfIn PDF document text
    • https://cncunse.com/d/files/xawujoluvokudevow.pdfIn PDF document text
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135ca73ba33e---63976937963.pdfIn PDF document text
    • http://master-sign.ru/ckfinder/userfiles/files/burisisiviburojodewod.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=verbal+judo+the+gentle+art+of+persuasion+pdfPDF 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_off0000c765.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC765 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000df7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF7C 11116 bytes
SHA-256: afc5a822da7ada65ea4f792c81cfdd061de57fb418e9566440b6e3c466711d1f
font_02_sfnt_off0000f8d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8D9 17220 bytes
SHA-256: 96a62182bfff76b952b09995e62decfc82f72ac87a9dc6b83d13a6e274cbfec5