Malicious PDF — malware analysis report

Static analysis result for SHA-256 73832fb8642be7dd…

MALICIOUS

PDF

84.5 KB Created: 2021-09-17 09:32:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: dcb1c368b5654470dded0967face7076 SHA-1: 2b20f8cc7ee704971cfac46a2bda62f56f3b4eca SHA-256: 73832fb8642be7dd1467b3d5dddbdf03cb8ad391fe74126599858e85d59bdd53
156 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://mbfeed.vn/upload/files/jokikutepuno.pdf In PDF document text
    • https://esterkins.de/ckfinder/userfiles/files/10507075592.pdfIn PDF document text
    • https://www.azulejositurry.com/wp-content/plugins/super-forms/uploads/php/files/q0568vbf8umuno1linnprjcmj6/dovobadujazajegokutafoxup.pdfIn PDF document text
    • https://matraci.info/UserFiles/File/zovikisugewinurivipigi.pdfIn PDF document text
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/16131571ec8cbf---gefoguxiredibogugo.pdfIn PDF document text
    • http://dienlanhlongan.com/upload/files/menipimuxarugug.pdfIn PDF document text
    • http://klick-tipp.info/ckfinder/userfiles/publics/files/tiwitatomizijugirafi.pdfIn PDF document text
    • http://yasairamenbar.com/uploads/files/lupakedisotelijamim.pdfIn PDF document text
    • https://adoz.cz/ckfinder/userfiles/files/85831300729.pdfIn PDF document text
    • https://binarbaidfabrication.com/public_html/userfiles/file/25825066804.pdfIn PDF document text
    • https://dallaslandscapedesign.com/media/files/82775014785.pdfIn PDF document text
    • http://cppzone.ru/users/blogs/file/losufipukonubaxewabap.pdfIn PDF document text
    • http://praguetransfer.com/files/file/xinixisofok.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fdf9c4e427---xizibubofiwanadusutulu.pdfIn PDF document text
    • http://ccswcd.com/userfiles/file/82573669893.pdfIn PDF document text
    • http://ombs.ru/uploads/files/90222074102.pdfIn PDF document text
    • http://2013.letnifestiwal.pl/ckfinder/userfiles/files/godojufajageduwi.pdfIn PDF document text
    • http://www.louthadventures.ie/wp-content/plugins/formcraft/file-upload/server/content/files/16132a03a23dc3---75613562998.pdfIn PDF document text
    • http://lpsa.cz/userfiles/file/20241840851.pdfIn PDF document text
    • https://petek.biz/resimler/files/78209738425.pdfIn PDF document text
    • https://romalasergroup.com/userfiles/files/nunegoputebonedofuwide.pdfIn PDF document text
    • http://sziszolg.hu/editor_up/5411134004.pdfIn PDF document text
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/16136543b18108---xejamoxu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=how+to+recover+photos+after+factory+reset+android+without+computerPDF link annotation
    • https://www.thc.gda.pl/ckfinder/userfiles/files/13899624064.pdfIn PDF document text
    • 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_off0000e3b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3B5 11196 bytes
SHA-256: 9478244e233806123ea7194ff660cf1813d15a12743c85724dd3c8c1dd4b4e14
font_01_sfnt_off0000fdcf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDCF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000115e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115E1 17764 bytes
SHA-256: 33a56c90c3f462422077bc3ac9826d47a0294b552c566ef3fec1049854a76ceb