Malicious PDF — malware analysis report

Static analysis result for SHA-256 d5cea73d7c134838…

MALICIOUS

PDF

87.3 KB Created: 2021-08-29 06:57:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: be9fc75d36e1e58aa8db946a732e6b6f SHA-1: f90a1d2d461a54cd7fca16f337ad562bda70c7c4 SHA-256: d5cea73d7c134838d373f7a30444b2e43cc0b75d968cc5750328ccb21fb7cdf5
156 Risk Score

Malware Insights

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

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier with high confidence. Static analysis revealed it functions as a link farm, containing numerous URLs pointing to compromised WordPress sites. These sites, in turn, host other PDF files, suggesting a multi-stage attack designed to lead users to malicious content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9919

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://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/ccc40f285180c81707a81c336c74af05/vunozukelanaka.pdf
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/161281cd152772---bodezenipikigegowevako.pdf
    • https://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160a6864c243d4---gupalon.pdf
    • http://gibisch.info/files/files/3335903863.pdf
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/160826b739bf7f---vilexixikodibegixetize.pdf
    • http://www.lightingandhvacexpo.com/wp-content/plugins/super-forms/uploads/php/files/f17ef6d952fea520ef77cc1af1f694a4/51665738412.pdf
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608aabd60b499---97817369659.pdf
    • https://by-express.com/upfiles/editor/files/dakukevodar.pdf
    • http://modnyi-buket.ru/uploads/files/2151557731.pdf
    • http://asckhn.com/acskhn/userfiles/file/zofoxupafi.pdf
    • http://es-umzuege-transporte.de/wp-content/plugins/super-forms/uploads/php/files/dc8eb3cfad462e36e3a68c994e526d9e/31816294475.pdf
    • http://cuboni.com/uploadfile/hong202106111900444468.pdf
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/61f541c11905d3c5beddf9cc2fb84f23/liralixakevavadijenugabi.pdf
    • https://noticky.net/akce/fotky/file/56488248685.pdf
    • http://aihyang.com/userfiles/file/71708375882.pdf
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/1606c68dfb7b1f---46385306249.pdf
    • https://cleartunemonitors.com/ckfinder/userfiles/files/nitepisut.pdf
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a14c3c8b79b---kamamipuk.pdf
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca9143154b---83305483704.pdf
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/0gv69n1m6k5r8cq53julns3kmu/80662379385.pdf
    • http://www.pics4us.de/userfiles/file/54233281281.pdf
    • https://www.lenoir-elec.com/wp-content/plugins/super-forms/uploads/php/files/agdc0bsoduapg6edneqjtk0fih/bawegixafe.pdf
    • http://debandhelder.nl/ckfinder/userfiles/files/dasenakobolafegekulemifir.pdf
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608bb9f0ce0b8---98377655490.pdf
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609841437867a---mupizaferipebexagi.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=jalapeno+cheese+bread
    • http://e1pl2.nazwa.pl/busy/fotki/file/67974738927.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_off0000ed52.bin
61a3654195ff6644730f3090551dd666dd9da70e3bc19990bbdacdc5b06d86fa
pdf-font-stream PDF embedded font (sfnt) at offset 0xED52 18980 bytes
font_01_sfnt_off00011d7a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D7A 16792 bytes
font_02_sfnt_off00013591.bin
6860a3ad426c00232ab1acf49caa1841174c622045778e47594f72789966bedd
pdf-font-stream PDF embedded font (sfnt) at offset 0x13591 10552 bytes