Malicious PDF — malware analysis report

Static analysis result for SHA-256 88dd9eeb861e3f39…

MALICIOUS

PDF

88.4 KB Created: 2021-09-01 04:11:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 61ad22701958f68aaba66a8758aa492d SHA-1: 1629938c26379d241500967668b2692553d84021 SHA-256: 88dd9eeb861e3f39112821543ec9046b1586e718c5606af0a6bdf9ca77cb3116
156 Risk Score

Malware Insights

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

The ML classifier and ClamAV detection strongly indicate maliciousness. The PDF contains numerous links pointing to potentially compromised CMS upload directories and disposable hosting, suggesting a link farm for SEO manipulation or to distribute further payloads. While no scripts were explicitly extracted, the nature of the links and the PDF structure suggest it's designed to lure users to malicious content, likely involving exploitation of PDF vulnerabilities or social engineering.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://esterkins.de/ckfinder/userfiles/files/sifore.pdf In PDF document text
    • http://dorisemitchell.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/dutasurovigixawisapej.pdfIn PDF document text
    • http://donleroy.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/susujowasozupewos.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2d752cf852---kokuvenelidapem.pdfIn PDF document text
    • https://www.apartamentselsllacs.com/wp-content/plugins/super-forms/uploads/php/files/hlgai59sgqc1atcm0rp8k3s7d1/fowodotataxefobuvukuwazal.pdfIn PDF document text
    • https://gifarlcm.com/upfiles/editor/files/56918693590.pdfIn PDF document text
    • http://virtualcharityevents.com/vce_cake/files/files/zokizekenar.pdfIn PDF document text
    • http://thegioituigiay.net/uploads/files/81957521455.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d183176bc0---42564705815.pdfIn PDF document text
    • http://lysfyyy.com/upload/files/12945963602.pdfIn PDF document text
    • https://jagominum.com/contents/files/73369406474.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160843e9e5cf19---21210316511.pdfIn PDF document text
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a791e6469d7---lijimaranavetifu.pdfIn PDF document text
    • http://one9five.com/userfiles/files/divozinewibisakefaleki.pdfIn PDF document text
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/a68dee77f3354236d252d7f4498de0b0/21137277388.pdfIn PDF document text
    • http://saktigroup.in/uploads/wufalunu.pdfIn PDF document text
    • http://bptramptour.pl/files/file/jowes.pdfIn PDF document text
    • http://richmore.kr/uploadfile/fckeditor/file/5799579050.pdfIn PDF document text
    • http://hosungtour.net/FileData/ckfinder/files/20210622_117D092A3D9199A4.pdfIn PDF document text
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160de6bb8ae2fa---wasimotugebogajetixiwu.pdfIn PDF document text
    • http://usarsenal.it/userfiles/files/8019343936.pdfIn PDF document text
    • http://www.lifestaralberta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612181439ca2f---57747409114.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=what+is+the+process+of+changing+liquid+to+solidPDF 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_off0000f186.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF186 18548 bytes
SHA-256: 3847376fbab4c032272573628c46654c9b55516812265fa0c40eeb2e4aad7193
font_01_sfnt_off00012126.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12126 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001393d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1393D 11140 bytes
SHA-256: a2eac2d48526f9b48c6a3ed6a42aacd4fc2d8b9a340227e4dbe67b535b466df1

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