Malicious PDF — malware analysis report

Static analysis result for SHA-256 c550f3dbfa443366…

MALICIOUS

PDF

70.7 KB Created: 2021-09-09 12:56:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: d034a3b589e2a5ce02c572c813dbd19c SHA-1: f339ac978e8b76d541937cecca4aa3923490059f SHA-256: c550f3dbfa443366c1fa8a2d891ea1f7d6448848d44a4cd08f4834aed0dbfc21
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, and exhibits characteristics of a link farm. Multiple heuristics indicate the PDF contains numerous links pointing to various domains, some of which are hosted on compromised CMS uploads. The embedded URLs suggest an attempt to redirect users to external, potentially malicious, content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://www.museopizarra.com/ckfinder/userfiles/files/80718836896.pdf In PDF document text
    • http://stnicholasway.com/userfiles/file/62274101634.pdfIn PDF document text
    • http://bekkercoon.ru/ckfinder/userfiles/files/guviritupevo.pdfIn PDF document text
    • http://mmbc.cz/_data/user_files/file/lekenufoxepafixonorub.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16132c5c2b1a90---lirapilox.pdfIn PDF document text
    • http://hillsclinic.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/4751524585.pdfIn PDF document text
    • http://monthclean.com/uploads/files/202109051728328918.pdfIn PDF document text
    • https://styliststudios.com/imagesTE/file/72097933320.pdfIn PDF document text
    • http://allaboutdowney.com/userimages/bukimogisazewafipajuboju.pdfIn PDF document text
    • https://rosanaalvarracin.com/userfiles/file/batuj.pdfIn PDF document text
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16133871102a98---texomakesugowitegolejut.pdfIn PDF document text
    • http://trunglamdecor.com/uploads/userfiles/file/29979491348.pdfIn PDF document text
    • http://shrlie.com/upload_fck/file/2021-9-9/20210909081534922786.pdfIn PDF document text
    • http://www.groupementpecheduloir.com/ckfinder/userfiles/files/bewizutaluwasimoluxolerel.pdfIn PDF document text
    • http://www.gunyagder.org.tr/wp-content/plugins/super-forms/uploads/php/files/q31mdo36p36am13am5elk0eak3/luzubikonunenewaxudofoziv.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/16136d3e34d59e---35034155692.pdfIn PDF document text
    • http://teenmag.cz/userfiles/file/8078145155.pdfIn PDF document text
    • http://manavpublicschool.org/manav/userfiles/file/47194488379.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130140b7e192---49323558868.pdfIn PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161301c6186a03---71760995744.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=cutting+edge+pre+intermediate+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_off0000b2c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2C0 16764 bytes
SHA-256: bdcc7ca5518c6215860dbf53285af4eaf86e2399e6c80d12bbb4d9a9b16317fa
font_01_sfnt_off0000ddcd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDCD 10636 bytes
SHA-256: 93f9a0e922dc7e0ee3e9d1a58a84648280e134b8c8d1b3184ce945a32c93800d
font_02_sfnt_off0000f5ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5EC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1