Malicious PDF — malware analysis report

Static analysis result for SHA-256 25b2eb682714ca73…

MALICIOUS

PDF

92.5 KB Created: 2021-07-01 16:50:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 420426f47b77916c7b0b724806baff22 SHA-1: e5525ba2a59e60d22850794417598b172c9af4d1 SHA-256: 25b2eb682714ca736c085dca1c6b070166efe480eaa1a82384e322b7d3ae33e7
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites utilizing the Formcraft plugin for file uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or SEO spam. The document body is heavily obfuscated and unreadable, providing no direct user-facing content, but the heuristic firings clearly point to a link farm strategy.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a59f2602472---wukumowuxilan.pdf
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a9b1560fdd7---21991019589.pdf
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/1607c9fdd23541---50340709998.pdf
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607033fa67e97---terejajosukujuzegoda.pdf
    • http://grupogmec.com/wp-content/plugins/formcraft/file-upload/server/content/files/160707e32b99bc---kuvesetopelewalul.pdf
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af69f1cc800---1450683837.pdf
    • https://www.m2asolutions.com/wp-content/plugins/super-forms/uploads/php/files/2c2b900c64ad10dc37ee9a2647b6c6ac/menari.pdf
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/796000edb4828979f35fe68336c2f644/fazaj.pdf
    • https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/2vp1s73r8a36egck8qo6j24dei/20509035706.pdf
    • http://bagiez.com/userfiles/file/99765553157.pdf
    • https://iominneapolis.com/wp-content/plugins/super-forms/uploads/php/files/4e87a52dc550e7dbdf59eab2db74fedb/22210327461.pdf
    • https://sancarspune.com/wp-content/plugins/super-forms/uploads/php/files/7475f60e1e7f64a20611e8ff0dea183b/jusiketodedejola.pdf
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/cbb6fe11fd7afd108db5c66ca26191d0/zosogasowegupu.pdf
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16076acb70724f---28073679859.pdf
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606f1d2a1ff44---buseziror.pdf
    • https://afriqueitnews.com/wp-content/plugins/super-forms/uploads/php/files/641f74201117b3e8680d52afe2118649/bulavidanelexarodovoruzet.pdf
    • http://tencanpowder.com/d/files/tovufisimuzuvoziv.pdf
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c4ed8a6814---53832100685.pdf
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160979df6467a6---jiligajej.pdf
    • https://completecollegestrategies.com/wp-content/plugins/super-forms/uploads/php/files/68f7c85f8b3ca98349e29c64ba138e8f/zefotot.pdf
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7ef0679c6b---kusupemazaxetaro.pdf
    • http://braciszewska-klimek.pl/fck_files/file/35581354801.pdf
    • https://sunsoftinfoway.net/ckfinder/userfiles/files/kutavutepozagewegowof.pdf
    • http://kruengrangthai.com/files/files/94575090454.pdf
    • https://bleikss.com/userfiles/file/85877969203.pdf
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1606f5754ba895---65606997418.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=counterspell+wow+classic
    • 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_off000104f1.bin
140e04538a6b8acfe11c36ffb7d3d89c29912bdd7aafa6e1cd9da063e3d8a049
pdf-font-stream PDF embedded font (sfnt) at offset 0x104F1 10584 bytes
font_01_sfnt_off00011d61.bin
2796b068ca2012aa0ecb98e0b1ad68584f8e051fccb768c7f3ab49c3f36dc936
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D61 17808 bytes
font_02_sfnt_off00014c66.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14C66 16792 bytes