Malicious PDF — malware analysis report

Static analysis result for SHA-256 3710ae53a473b5f0…

MALICIOUS

PDF

75.2 KB Created: 2021-09-02 13:46:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e4ed3583298caddb0191c3a09b9b173c SHA-1: 8361e50a42b468abb1a580e160c287dd555560ba SHA-256: 3710ae53a473b5f0261419f37bf671e4cb6df4aa5a3755e52676a15502bab2b7
156 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous external URLs, many pointing to compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is unreadable, but the heuristics and URL analysis confirm its function as a malicious link aggregator.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9939

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://svazekobciorlice.cz/userfiles/file/bugane.pdf In PDF document text
    • https://5a.ro/ckfinder/userfiles/files/degarewigipitezexit.pdfIn PDF document text
    • http://rahway1968.com/clients/5/53/53e48f2724afc57738bbbcfbfdbdad27/File/malejamavagisaletega.pdfIn PDF document text
    • http://u15.ch/ckfinder/userfiles/files/7593217375.pdfIn PDF document text
    • https://law.com.sg/wp-content/plugins/super-forms/uploads/php/files/a7acc6d8038d2d7418261de66171e926/7286566032.pdfIn PDF document text
    • http://seoulmenu.com/uploads/files/3453068040.pdfIn PDF document text
    • http://dexgerm.com/data/file/userfiles/files/gamevufabopelifowagoxofag.pdfIn PDF document text
    • http://divorce-difficile.fr/userfiles/file/kamuvisiverate.pdfIn PDF document text
    • http://thm-holding.ru/wp-content/plugins/super-forms/uploads/php/files/358e30bdb0850a20b51db931310b73b1/fazukakidagemijofarijivo.pdfIn PDF document text
    • https://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/160b35f2ccc449---sapikujezenusixinin.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/faknmgn6dgabas69cpv0ch5cg0/damezanidunutezez.pdfIn PDF document text
    • http://vinhomeshaiphong.net/app/webroot/img/files/dotusinutisokapegido.pdfIn PDF document text
    • http://sl-light.ru/design/img/upload/file/55007556867.pdfIn PDF document text
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/16085a27b791fc---vezovekimafewopabubute.pdfIn PDF document text
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/49fc0f3a5980edf871884251a6390815/79183781253.pdfIn PDF document text
    • http://matchedtubes.de/userfiles/file/59796830863.pdfIn PDF document text
    • https://bselink.com/userfiles/file/kuxatezu.pdfIn PDF document text
    • http://aelma.com/sites/default/userfiles/file/81547395945.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e6b11e2faa6---mofojixiluzav.pdfIn PDF document text
    • http://emaaravm.net/upload/files/81403801225.pdfIn PDF document text
    • http://bestapp4u.com/admin/uploadedfiles/file/11881431486.pdfIn PDF document text
    • http://signexpowholesale.com/project-new/christianbook/upload_images/file/furizagadagitexu.pdfIn PDF document text
    • http://crmrealty360degree.in/ci/userfiles/files/lusum.pdfIn PDF document text
    • http://yevres.fr/ckfinder/userfiles/files/49896923564.pdfIn PDF document text
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160922d2510204---60279778253.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ae76a59e14---50609536431.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=toefl+speaking+rubric+pdfPDF 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_off0000c2f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2F1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000db03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB03 16636 bytes
SHA-256: 21f6d59bcebd4b7400a6a1cc591ecd3e41414b4b29d5efa208123d73b9fdcba1
font_02_sfnt_off0001052e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1052E 10992 bytes
SHA-256: 6f6d89dd4228880151617df4b3e63c214827b43653580de986ff4ab5e1acda80