Malicious PDF — malware analysis report

Static analysis result for SHA-256 25cac168a85879f3…

MALICIOUS

PDF

90.4 KB Created: 2021-09-17 01:55:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c81f89860bd2e9730873d356786913d2 SHA-1: 3ed5e03296b19f66dd9cbee83545010a2fbaf12c SHA-256: 25cac168a85879f33c556aacdffa3a9ed9924c7b36150b83ba65b9b956e25041
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress sites, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. Although no scripts were explicitly extracted, the nature of the links and the heuristic firings point towards a malicious document, potentially leveraging embedded JavaScript for redirection or exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613bb64c38c9c---pekenagamiluju.pdf
    • http://aal.tw/uploads/htmlupload/files/koxudarug.pdf
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143c26fa2c29---88255721122.pdf
    • https://ckfinder.pamlskovnik.cz/ckfinder/userfiles/files/datowuwuxitetasufagaso.pdf
    • http://shangrilayunnan.com/ckfinder/userfiles/files/42666471152.pdf
    • http://royal-pizza.eu/files/file/zalojowi.pdf
    • http://sahamit.net/userfiles/file/volasujegadunodowo.pdf
    • http://www.santabriganti.org/admin/ckfinder/userfiles/files/kejemivaxanukonu.pdf
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16143c6aa5fc4c---95766161998.pdf
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/16136c14475852---61649736968.pdf
    • http://struttur-arch.it/userfiles/files/tolusesumipubumawowom.pdf
    • http://mirutte.com/newsfiles/files/48646061606.pdf
    • http://polishingmarblefloor.it/userfiles/files/bunekawifawaxelilujawan.pdf
    • https://etravelbox.com/scgtest/team-explore/uploads/files/nifofejejodemegigiz.pdf
    • https://bestofbucerias.com/upload/file/18465433486.pdf
    • http://bettaletroom.com/file_media/file_image/file/nodadodivabo.pdf
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/dp71000gokiue29q2h9ag5kdcl/64053862018.pdf
    • https://hongdung.vn/ckeditor/images/files/11971645911.pdf
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613ded3392174---95928464506.pdf
    • https://kamionosnyelvlecke.hu/userfiles/file/84091684977.pdf
    • http://www.keizerco.nl/userFiles/file/xafoz.pdf
    • http://hmondo.com/userData/board/file/608971548.pdf
    • http://veszpremkosar.hu/_user/file/zugowepajuxosujirilara.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=list+android+versions
    • 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_off0000ffac.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFFAC 16792 bytes
font_01_sfnt_off000117be.bin
7656199072d1b51ca977777557de787dc89e8f9c72245e2aaedbddd56563902a
pdf-font-stream PDF embedded font (sfnt) at offset 0x117BE 17564 bytes
font_02_sfnt_off0001451a.bin
e43e6ef18e72b067f3407402967c61155e869fa0b0af3d92e7612431de7a2007
pdf-font-stream PDF embedded font (sfnt) at offset 0x1451A 10216 bytes