Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3703f5ded7aec89…

MALICIOUS

PDF

82.1 KB Created: 2021-08-09 05:11:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 64898f677730d963f80c0984e39cd68f SHA-1: b137b1a2fddda63f66ff8b2d0cd65e8c78878dc7 SHA-256: b3703f5ded7aec890fbb3bb21215d822579d4242bf207b4815e37700ea5706a9
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised WordPress sites, which likely serve as a link farm to obscure the true destination. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for these links, suggesting an attempt to evade detection and distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 https://xn--interpeas-r6a.es/upload/files/74175128947.pdf In PDF document text
    • https://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/94ee85a845880b219b2bf69f4d61a538/zukigiveripumureguzax.pdfIn PDF document text
    • http://jirehenl.com/userfiles/file/221811332463.pdfIn PDF document text
    • https://phase1acoustics.com/wp-content/plugins/formcraft/file-upload/server/content/files/160861d75b19a9---sovuwoturawewirusulusumil.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b092bb2fc8f---67052249655.pdfIn PDF document text
    • http://xingyeknitting.com/userfiles/files/6651423055.pdfIn PDF document text
    • http://daehwa.info/uploaded/file/30392757732.pdfIn PDF document text
    • http://g-shocktou.com/user_file/file/bawikironosapilusolujom.pdfIn PDF document text
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/bnrqp9us8g79pu6h7r9joh007r/67358295730.pdfIn PDF document text
    • https://www.aserspa.net/wp-content/plugins/super-forms/uploads/php/files/fqsi4b1srp589adm1r2ou33i6u/80045740037.pdfIn PDF document text
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c8cd9eec96---61379632375.pdfIn PDF document text
    • http://psychanalyste-gard.fr/ckfinder/userfiles/files/63096913780.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16092cd3634d1f---37524527689.pdfIn PDF document text
    • http://goksirlambinowice.pl/img/upload/files/suxagosumebesulebolut.pdfIn PDF document text
    • http://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/2b1ae94cb729c995c915305c02a8cceb/65851010778.pdfIn PDF document text
    • http://malovanesklomh.cz/images/file/nufixilurotutamak.pdfIn PDF document text
    • http://zabradli-znerezu.cz/userfiles/file/15408354710.pdfIn PDF document text
    • https://bitree.ru/ckfinder/userfiles/files/fixoranaza.pdfIn PDF document text
    • http://cheumst.com/upload/fckeditor/file/11190884321.pdfIn PDF document text
    • http://nandeestationery.com/userfiles/files/xorakorafazukawoselepel.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/650f605e85f47172a833ab3dd06deb05/88546207570.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1609207ca1500e---90804709195.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607bd36a1b0d4---gonifomikejofoguxemare.pdfIn PDF document text
    • http://deeringbayrealestate.com/userfiles/files/3329635905.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=ralink+bluetooth+driver+for+windows+8.1+64+bit+hpPDF 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_off0000d8af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8AF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f0c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0C1 17508 bytes
SHA-256: 30bc73a870b194a446dbe262735a63449478bb3acbd4c1e701eb1bd2a91ffe12
font_02_sfnt_off00011ef6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EF6 11696 bytes
SHA-256: ebd56a3fe0b81f0c9c1da84254659ee875f1d3a0b0b89d099ab5c66aa733fe8a