Malicious PDF — malware analysis report

Static analysis result for SHA-256 c7a47b62301cbb29…

MALICIOUS

PDF

93.9 KB Created: 2021-09-08 17:11:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 6135fed3f80d257bad8b09dcfd4288a8 SHA-1: 235dd210b343d09157930b6657320277559d5190 SHA-256: c7a47b62301cbb29655b591340b1b9349b8e4d7a86c6557af672b47b29df822a
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users to malicious content. The 'wkhtmltopdf' authoring application suggests it may have been generated programmatically for this purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://dglytbt.com/upfolder/e/files/20210905223413.pdf In PDF document text
    • http://bftt.marketsearching.com/upload/files/51924475887.pdfIn PDF document text
    • https://damsindia.org/admin/uploads/file/76173235950.pdfIn PDF document text
    • http://thm-holding.ru/wp-content/plugins/super-forms/uploads/php/files/07cd30f88955594aad4ee56091a5645b/72818691755.pdfIn PDF document text
    • http://tuzy.pl/Upload/file/sikulosonegemafajusiguxus.pdfIn PDF document text
    • http://www.trisad.kz/ckfinder/userfiles/files/nivikesubajirinibanebo.pdfIn PDF document text
    • https://ximatinhdongnai.com/app/webroot/files/images/pages/files/vafurag.pdfIn PDF document text
    • http://rabotatver.ru/userfiles/admin/96862644071.pdfIn PDF document text
    • https://esvigo.com/upload/files/21618008526.pdfIn PDF document text
    • http://herbwaterthailand.com/userfiles/files/zigexilefi.pdfIn PDF document text
    • https://svenjakretschmer.com/ckfinder/userfiles/files/55418566535.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161309919d1129---gegemexufefi.pdfIn PDF document text
    • https://fmpride.com/wp-content/plugins/super-forms/uploads/php/files/8d8ecd507a15be937fffd3d4cec7028e/42144650505.pdfIn PDF document text
    • http://kemnhapkhau.com/upload/files/21977074604.pdfIn PDF document text
    • https://insolite.lu/img/userfiles/files/25400789265.pdfIn PDF document text
    • http://www.sospapa24.com/lib/ckfinder/imgupload/files/92788863429.pdfIn PDF document text
    • http://asid.rw/userfiles/file/69756368329.pdfIn PDF document text
    • http://wang023spa.com/userfiles/202109file/2021090721022070554.pdfIn PDF document text
    • https://delaneyllc.com/ckfinder/userfiles/files/25641954471.pdfIn PDF document text
    • http://zhouzhuanx.com/v15/Upload/file/202195153279134.pdfIn PDF document text
    • https://resttour.com/images/userfiles/files/37049695688.pdfIn PDF document text
    • https://dianthusindustrial.com/resimler/files/1991572773.pdfIn PDF document text
    • http://tropo-design.com/ckfinder/userfiles/files/45138817036.pdfIn PDF document text
    • http://dealershop.es/userfiles/file/17408793074.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=ultimate+guide+for+arduino+sensors+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_off0001087c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1087C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012093.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12093 10948 bytes
SHA-256: ef6859cba4592841ff91e543ca016f2ce09bca6edd82839db4de8ad406647dc4
font_02_sfnt_off000139ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139AB 18448 bytes
SHA-256: 4eb58a238b32eaeb6d32819d7dce2f0a6ce8bcc82741072b0a8d949752fc1aea