Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a61a3b77becbbf2…

MALICIOUS

PDF

69.1 KB Created: 2021-09-25 09:37:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: fc14e9cc28e5af9db4e211a5865b8964 SHA-1: f2fb3469f7cb0f0bb270a1072de6512eb30bbe61 SHA-256: 8a61a3b77becbbf2e15b232962adb496a1dc2ffb50edcf8a4fb1de7faa72282c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, many pointing to compromised WordPress sites hosting other PDF files, indicating a link farm designed to distribute malicious content. ClamAV detected this file as Pdf.Phishing.Trojan, and ML classifiers also flagged it as malicious. The presence of multiple external URIs and link farms suggests an attempt to lure users to malicious sites, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://qianxish.com/ckfind_image/files/fizogofesenowizaxubedoge.pdf In PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613349f52ad09---66905727755.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16137035551a2b---fotivejosugu.pdfIn PDF document text
    • https://feriaesotericadeatocha.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ef7c1e147d---boduzasikol.pdfIn PDF document text
    • http://ridendo.cz/files/file/52026001402.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/161327e69d8553---7154498184.pdfIn PDF document text
    • http://gimhaejazz.com/fckeditor/userfiles/image/xujitiwobazujopeliju.pdfIn PDF document text
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614d060e368de---97075914269.pdfIn PDF document text
    • https://cashcruis.ru/wp-content/plugins/super-forms/uploads/php/files/6f6331a5a65a8d5394a35407970fa99b/41108371502.pdfIn PDF document text
    • http://jump360.co/upload/files/20210902041241.pdfIn PDF document text
    • https://apexforestservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614c8e49083b5---retuluzu.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/1614921e2e8608---jimufesugurose.pdfIn PDF document text
    • http://crosswaysrecruitment.com/userfiles/file/romenudujofonolatujifap.pdfIn PDF document text
    • http://gazosilikatnn.ru/uploads/files/53971579331.pdfIn PDF document text
    • http://systempro.kr/userData/board/file/1125829660.pdfIn PDF document text
    • https://sapsda.com/SapmaUserfiles/file/53194688023.pdfIn PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/161483920424ac---97323371593.pdfIn PDF document text
    • http://duquenne-moteurs.fr/webroot/upload/files/werepa.pdfIn PDF document text
    • http://mesterteto.hu/userfiles/file/43693339678.pdfIn PDF document text
    • http://bjjiffy.com/upload/37439743078.pdfIn PDF document text
    • http://massimomoroni.it/userfiles/files/5823109473.pdfIn PDF document text
    • https://ambient-interier.cz/files/files/mepeledekuji.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=shell+shock+live+unblockedPDF 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_off0000b185.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB185 14756 bytes
SHA-256: 567ed35662237b3d90f4156c5558830f5e391768da1a226222e0b969663b0e85
font_01_sfnt_off0000d6a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6A0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000eeb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEB7 10580 bytes
SHA-256: 413b6da4f797edf2a12a79addedb1186ae36ec7164a94f3a1135fcde95f7d14e