Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf55bd26358b7d7b…

MALICIOUS

PDF

97.8 KB Created: 2021-06-27 14:20:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a3f38c3901495d592f4c3b21150ef7c8 SHA-1: 24c64e8d7cc80241b6066acf95138427003336c0 SHA-256: cf55bd26358b7d7b2eb6fe6893e9bf625a7ea92c2f63c6dcb171b1179fcb5aec
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to compromised WordPress uploads and other disposable hosting sites. While no scripts were explicitly extracted, the PDF structure and numerous embedded URLs suggest an attempt to redirect users to phishing or malware-hosting sites, likely delivered via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9784

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://queure.ru/uplcv?utm_term=the+elevation+in+boiling+point+of+a+solution+of+13.44+g+of+cucl2
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5b8b4e26e5---makove.pdf
    • http://flgr.ru/files/files/96980926309.pdf
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c753bfe5958---kuvifuwemidetodenum.pdf
    • http://busankid.com/webfiles/board/file///32766771433.pdf
    • http://asdgolfclubtoscana.com/writable/public/userfiles/file/64053427450.pdf
    • http://www.sport-konyv.hu/userfiles/file/52212495195.pdf
    • http://pantipplaza.com/userfiles/file/fonixagajijan.pdf
    • https://svingenieria.cl/userfiles/file/pipujilofetabova.pdf
    • http://n2nlah.org/UserFiles/file/70826823099.pdf
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/68f5ae22e249ec882e033948f1ba296e/dogidodidafuvimi.pdf
    • https://floorco.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/3129d3c3587a4a96fc6f988393ef0d42/5950941827.pdf
    • http://modnyi-buket.ru/uploads/files/jenad.pdf
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c2c9b21986---69813462405.pdf
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/blh89f2dpo3hbmoug2elf27hv0/libulotovomudamore.pdf
    • http://dailitara.lt/bites/uploads/file/81113853530.pdf
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9f4dd2c1c7---kakenipapolepefasukolax.pdf
    • http://congtyvima.com/images/Download/56779220197.pdf
    • http://jnnycc.org/userfiles/file/87686166577.pdf
    • https://unique.global/wp-content/plugins/super-forms/uploads/php/files/101b636ac68d96ce88b16816f163413b/valobusefojo.pdf
    • https://alajuusa.eemedia/contents/file/30209286373.pdf
    • https://protradingindia.net/userfiles/file/numewolise.pdf
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16090e356c4d88---tiratu.pdf
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083e6dd0aca0---wewotisavevinixajowag.pdf
    • https://www.northernillumination.com/wp-content/plugins/super-forms/uploads/php/files/0e86621f643084556454a8b74bd2cdb5/7267812840.pdf
    • http://ubest.ru/images/file/jitegivekeji.pdf
    • http://timatey.kz/wp-content/plugins/super-forms/uploads/php/files/48mc9vtmbpflu76vfa0tsdplv6/70735535843.pdf
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/fenodesogefufutibul.pdf
    • 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_off0001162a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1162A 16792 bytes
font_01_sfnt_off00012e41.bin
376ddea4cc123a270f38f13ea8b8a5f0f2bed333288b85d5f30be8f19ec724d5
pdf-font-stream PDF embedded font (sfnt) at offset 0x12E41 11416 bytes
font_02_sfnt_off0001491a.bin
08d2c4b566a23ba1f149d5116c6ecb263f610be229bf95d22e65065456a991ec
pdf-font-stream PDF embedded font (sfnt) at offset 0x1491A 18364 bytes