Malicious PDF — malware analysis report

Static analysis result for SHA-256 535fa62ae1e4eaff…

MALICIOUS

PDF

71.1 KB Created: 2021-09-03 08:42:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: b9fe08d4fd17b4426fb2ff4511b863c5 SHA-1: a6fc66b9d27af3af065b5c4ce2db248e651a7993 SHA-256: 535fa62ae1e4eaff6b32c9ab95db32e38e3d8010d4a207e5eec3f27c7edc1102
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm pointing to numerous external PDF files, many hosted on compromised CMS upload directories. This suggests a tactic to manipulate search engine results or to distribute further malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://theatresaucinema.fr/uploads/file/vugajinorugapuvomudutena.pdf In PDF document text
    • http://customize.fr/fckeditor/editor/filemanager/connectors/php/img/Editor/file/29993053183.pdfIn PDF document text
    • http://fcraregistration.com/UploadedData/file/tobez.pdfIn PDF document text
    • https://pensiuneavalentina.ro/app/webroot/file/69028972287.pdfIn PDF document text
    • http://brkvinc.com/userfiles/file/17027252717.pdfIn PDF document text
    • https://kimtuong.vn/isc/public/files/fckupload/file/lininiwulozigivut.pdfIn PDF document text
    • http://xn----gtbercbfedtm3b.xn--p1ai/admin/ckfinder/userfiles/files/zonewaboguzovub.pdfIn PDF document text
    • https://www.themeshcowork.com/wp-content/plugins/super-forms/uploads/php/files/9398e5e05239e0b47ad637aa215359f8/kerivifixiwatiwan.pdfIn PDF document text
    • https://youstore21.com/wp-content/plugins/super-forms/uploads/php/files/025babca1971b62835787e23a78a79c2/78483759350.pdfIn PDF document text
    • https://bestmiamiturf.com/wp-content/plugins/super-forms/uploads/php/files/66da589fa3e6ee3f2e33ac6f98af9438/bojubakorobajinagorekud.pdfIn PDF document text
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/160869f5f7cf97---givojanijutivuvoj.pdfIn PDF document text
    • http://ukrainski-rosyjski.pl/userfiles/file/kesutivawumipipuwonof.pdfIn PDF document text
    • https://sportli.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160985a060cda1---81474082557.pdfIn PDF document text
    • http://aeronautike.com/userfiles/file/16274281061.pdfIn PDF document text
    • http://alnoorcity.com/userfiles/file/74240233483.pdfIn PDF document text
    • https://homini.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16078f009020aa---nelebajalonusukemasaloxu.pdfIn PDF document text
    • https://lightingsystemscol.com/wp-content/plugins/super-forms/uploads/php/files/d46d8152a751d1787b3819c3c859e9c5/78286197473.pdfIn PDF document text
    • http://royalgroup.at/tmp/xikevugelodiz.pdfIn PDF document text
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160e92ab38d549---32809007550.pdfIn PDF document text
    • http://angelojrobles.com/admin_initial_test/userfiles/file/51854839459.pdfIn PDF document text
    • http://xlsferrosilicon.com/d/files/gesorikifikizis.pdfIn PDF document text
    • https://shevtsov-art.com/uploads/files/sidufidepekeditiniri.pdfIn PDF document text
    • https://www.straightmyteeth.eu/wp-content/plugins/super-forms/uploads/php/files/b7c8d637f6905b46380dc19e35428f1e/9081891080.pdfIn PDF document text
    • https://bjjewels.net/nbloom/fckuploads/file/berekasek.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=calculus+larson+11th+edition+pdf+downloadPDF 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_off0000b4d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4D9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ccf0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCF0 10988 bytes
SHA-256: 8a704e1af9dec1ecc4cf91498d5a223704391b86fa03a823d5de3ded6356a637
font_02_sfnt_off0000e67c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE67C 15904 bytes
SHA-256: 28ec488e04097a3a372ce1afe8f02d22ce4fb0d92a7141bcf1613476058eabf5