Malicious PDF — malware analysis report

Static analysis result for SHA-256 51e88000bf9a2d7c…

MALICIOUS

PDF

80.2 KB Created: 2021-09-09 03:46:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a925c240bd8643b9f57eeb52ffc6097d SHA-1: 27eb30af890b948b76854322a2f5a51c56453fed SHA-256: 51e88000bf9a2d7cc6a6e9cfc967be123cc3d00444208b9db7ee6abe8de22af4
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to lure users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://peter-crooks.com/userfiles/file/pupavodumakalewagabusi.pdf
    • http://la-roofers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161378f8478a42---finugumisekefazit.pdf
    • https://smlstripedbass.com/home/rock/public_html/ckfinder/userfiles/files/23808824796.pdf
    • http://planao.com/ckfinder/userfiles/files/27040621676.pdf
    • http://metrocars.london/survey/userfiles/files/kijelixuvix.pdf
    • http://lenosada.sk/editor_uploads/files/ginegejutexodepawuduvukit.pdf
    • http://chinazzjx.com/d/files/rajod.pdf
    • http://jrecchina.com/ckeditor/ckfinder/userfiles/files/kipawaxizokobuba.pdf
    • http://federicozucchettiarchitetto.eu/userfiles/files/31965130782.pdf
    • https://grandplaza.bg/uploads/assets/file/bezalu.pdf
    • http://rocincorporated.com/domain.com/images/dynamic_pages/file/50486311549.pdf
    • https://dacola.com/upload/files/33957732556.pdf
    • http://imreelectric.sk/uploads/file/79389334890.pdf
    • https://castel.ro/userfiles/file/lefedetoraxogogokewumive.pdf
    • https://imagebeaute.fr/userfiles/file/28725364248.pdf
    • http://lempreintedubois.fr/userfiles/lempreintedubois.fr/file/81278375521.pdf
    • https://culturasiapamplona.com/guiarte_userfiles/files/72325446070.pdf
    • https://giolog.biz/images/bulk_images/files/wuvadajesuviwuv.pdf
    • http://dostrojar.sk/UserFiles/file/93539079123.pdf
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130453d3c0cb---zumemutolonedofewexutowe.pdf
    • https://nikunjfoundation.org/ckfinder/userfiles/files/dojopulewevu.pdf
    • http://cudicio.it/images/file/sowupenarutukitirepodewap.pdf
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130ede0b3f4e---20703279370.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=auditing+a+practical+approach+2e+pdf
    • 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_off0000d8b9.bin
4825ec083ac48ca6f0ad115a55fe9131ae6faf62c81a86f6e6f0e66f6b298740
pdf-font-stream PDF embedded font (sfnt) at offset 0xD8B9 16276 bytes
font_01_sfnt_off00010251.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10251 16792 bytes
font_02_sfnt_off00011a68.bin
f6f9b8cc8179e2d430954d86f526843127efee8a5aa8ce9067acf1e5b48e4e55
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A68 10932 bytes