Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4628a8dc0f0dfa7…

MALICIOUS

PDF

69.1 KB Created: 2021-09-29 11:05:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 987611374614378fc7c8e6fb608d260c SHA-1: 90e38428bf76ce1cf5cf1631b33ef9078d6554e1 SHA-256: f4628a8dc0f0dfa798b1077e3035bb8953eb939f3a3b46795ebb513e5efb9ed1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a link farm pointing to multiple distinct hosts, many of which appear to be compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites.

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://wintec-samu.hu/uploads/files/20651650844.pdf In PDF document text
    • http://www.accl-calibration.com/login/ckfinder/userfiles/files/57355742395.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613223d011aba---41271848918.pdfIn PDF document text
    • http://freeware-software-download.de/uploads/editor/file/48771075720.pdfIn PDF document text
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/1613f9a7d36b72---51629137566.pdfIn PDF document text
    • http://wannawwannie.pl/userfiles/file/sodadavufe.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614caf034f4ab---23505381892.pdfIn PDF document text
    • http://www.cddfct.com/up_files/file/selogejibojapilovokizo.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139206e62596---lukorurururaselidutat.pdfIn PDF document text
    • http://yacpa.org/yacpafiles/file/28885571264.pdfIn PDF document text
    • http://c2mag.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138bf16e8e35---35647329316.pdfIn PDF document text
    • http://sarljarry.com/userfiles/file/32479178869.pdfIn PDF document text
    • http://accronline.com/userfiles/file/nisabevepupademuzi.pdfIn PDF document text
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614735f74c8a3---kofuvixesakazowiluzuzurif.pdfIn PDF document text
    • https://rjpexport.com/files/74025511067.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a3db3643f7---40346993237.pdfIn PDF document text
    • http://garankuccu.com/upload/fckimagesfile/1df37680e130f23752c9a7c1246c5d49.pdfIn PDF document text
    • https://shopexpert.com/app/webroot/files/userfiles/files/47589559494.pdfIn PDF document text
    • http://bolt.fo/public_html/userfiles/files/mutasugojuv.pdfIn PDF document text
    • https://ises.ca/phpsites/vertical_living/uploads/file/36845880654.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=dragon+ball+z+episode+namesPDF 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_off0000ae90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE90 15816 bytes
SHA-256: 1dc57ebae89f2d55a368073d5d6cebf69ee0228a6c6aca29d330c6713c759e42
font_01_sfnt_off0000d612.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD612 10836 bytes
SHA-256: 292e5259519e883ddf5f1939a054b51e37aca8a5b50bf199b5d8e7a8bbcb5f03
font_02_sfnt_off0000ee91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE91 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1