Malicious PDF — malware analysis report

Static analysis result for SHA-256 fdb10244575c5797…

MALICIOUS

PDF

94.0 KB Created: 2021-06-26 01:02:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: c0ea5d407f569b79e3fb939be7504d8a SHA-1: 528ecd2335371943e276a98d7630e2db3a145097 SHA-256: fdb10244575c5797608c71360b9067eb9b33d759b319ab951095811d8f86c9f3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, with multiple heuristics indicating it is a link farm pointing to compromised CMS upload storage. The PDF contains numerous external URIs, suggesting it is designed to redirect users to potentially malicious websites. No scripts were extracted, but the overall structure and heuristic firings strongly suggest a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

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 https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/160c21024a0579---520674147.pdf In PDF document text
    • http://russkiivopros.com/images/FCKeditor/file/94996536390.pdfIn PDF document text
    • http://mega.kz/media/upload/files/33248670917.pdfIn PDF document text
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/de9081054c77c5098c6738b0c1905f2d/69293048468.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a573ad54fd5---nosinadi.pdfIn PDF document text
    • https://seataclightingalaska.com/wp-content/plugins/super-forms/uploads/php/files/5217a82efc15f20b3d00fa7500da337c/vitefobagobumupuwofel.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a775883e455---90845507862.pdfIn PDF document text
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a64fc542edc---58578365845.pdfIn PDF document text
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609e875176bd7---wuxobulujoko.pdfIn PDF document text
    • https://www.ogblfrontaliers.fr/wp-content/plugins/super-forms/uploads/php/files/kjr9452o710fb2lrc3rn39dv0t/doxavuzuwifufulilinuke.pdfIn PDF document text
    • http://www.lauricedale.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606c831b86c5b---83411515754.pdfIn PDF document text
    • https://tavcam.com/upload/ckfinder/files/67251087648.pdfIn PDF document text
    • https://promocionesnma.com/wp-content/plugins/super-forms/uploads/php/files/59eb45e04c96f055a8e97c3df58ff300/wugusaxemisuvumulokezi.pdfIn PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609cb29d9cd30---kigavumajixoxodagokini.pdfIn PDF document text
    • http://ejmk.com/ej/upload/files/gijalawodezev.pdfIn PDF document text
    • http://eurogeographyjournal.eu/admin/fckfiles/file/2718075957.pdfIn PDF document text
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/ah02mbob8ve785inhigffeh8rr/bagideja.pdfIn PDF document text
    • http://heilpraxis-pankow.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608e69bcbec64---29198497960.pdfIn PDF document text
    • https://www.andrecampbell.ca/wp-content/plugins/super-forms/uploads/php/files/488ce534c8a90b24e6e9ac7477d6f5d2/46957022686.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/e7912316d86742936fabb5c3bb1b9e95/18320969227.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609dc5d311fb7---89281379798.pdfIn PDF document text
    • http://jointrilogy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c301e8ee75---madoxigul.pdfIn PDF document text
    • https://avgdesign.com/userfiles/file/zipasivitinipulimavaj.pdfIn PDF document text
    • https://asaptransfers.co.uk/wp-content/plugins/super-forms/uploads/php/files/02qsjqg5jrtdjcrc6t1c965h02/56055250889.pdfIn PDF document text
    • http://isystemlab.com/admin/ckfinder/userfiles/files/80927681367.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=best+answers+to+interview+questionPDF 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_off00010bed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BED 17636 bytes
SHA-256: aa821a3da4a716954fca90f4dcc473d1404a030ac9ab9a5c2a2e3943b4418e6e
font_01_sfnt_off00013a62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A62 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015279.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15279 10504 bytes
SHA-256: 7e89d117e10cd7e98a129ea3607673a41b5999114b9d3f6cf9b291992e13a715