Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf25572cb2be92d4…

MALICIOUS

PDF

96.1 KB Created: 2021-08-05 19:04:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: ff24db4b414ce3f81108d582f2ffdb9a SHA-1: bd3e8ef1bccdfc89f2095dcf8c0499ef0a7b0962 SHA-256: cf25572cb2be92d4d01496cb32ffa540bc05bb17f28851a1bf941012e1df8b84
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm. Multiple heuristics indicate the PDF contains numerous external URIs and links pointing to potentially compromised CMS upload storage and disposable hosting. The document body is heavily obfuscated, preventing analysis of its direct content, but the presence of embedded URLs and the link farm nature strongly suggest a malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://wsp.pl/userfiles/file/lovegiwasozubumokolijig.pdf In PDF document text
    • http://allaboutdowney.com/userimages/45938965661.pdfIn PDF document text
    • http://xn--b1agjlwjc3g.xn--p1ai/ckfinder/userfiles/files/jonamakerazedujumefeta.pdfIn PDF document text
    • http://www.hgbehringer.de/img/files/files/degagexodadalasesaj.pdfIn PDF document text
    • https://afra24.com/basefile/afra24/files/jivabekisezo.pdfIn PDF document text
    • http://www.tomasjelinek.com/img/pub/file/jijosexusasuda.pdfIn PDF document text
    • https://consurs.ro/ckfinder/userfiles/files/69222482160.pdfIn PDF document text
    • http://giasuthanhdat.vn/Images_upload/files/81839285876.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a1f16635a0f---resibowozutu.pdfIn PDF document text
    • http://www.korayozelguvenlik.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076eb8a00113---zowojoje.pdfIn PDF document text
    • https://cananalimdar.com/wp-content/plugins/super-forms/uploads/php/files/vq932h94um1gb12ka6vr914eob/49769458056.pdfIn PDF document text
    • http://haozuowenwang.com/imagefiles/file/bazozuzewuxipoma.pdfIn PDF document text
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/160adac1526be1---gipewobodiludoximuw.pdfIn PDF document text
    • https://kit-veron.my/ckfinder/userfiles/files/wixirosijonugami.pdfIn PDF document text
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/72f17b55b001a3af4585f684c3419500/91385015339.pdfIn PDF document text
    • http://www.empresasdelimpeza.info/wp-content/plugins/formcraft/file-upload/server/content/files/1608a025239067---24540444412.pdfIn PDF document text
    • https://h1t-url12shio-turbo.com/contents//files/83260483571.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb95ed2d4b1---jevokuxad.pdfIn PDF document text
    • https://yournew.site/wp-content/plugins/super-forms/uploads/php/files/k8mgobuqoaeev65b3oagak00le/madizeveteritaditekokiga.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160d66540c21a3---lurof.pdfIn PDF document text
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fb698d614f---66711741988.pdfIn PDF document text
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160cecf4446bc8---zigunurafe.pdfIn PDF document text
    • https://www.couleurs-et-jardin.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1606fb164f1c03---subefaz.pdfIn PDF document text
    • http://bixenony.com/userfiles/files/jumalan.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=civ+6+germany+strategy+rise+and+fallPDF 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_off00010e1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E1C 19720 bytes
SHA-256: bcf0cda931ef513a1db98724d9370a010e2ff4cc5a66400e777cfb436a7b8110
font_01_sfnt_off00013ff3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13FF3 10956 bytes
SHA-256: 993c1aad149b0932f147a296d66c5da1d9b9a00ed9a7949094622bb401c87e51
font_02_sfnt_off0001593f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1593F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1