Malicious PDF — malware analysis report

Static analysis result for SHA-256 5340a23dc012a5f5…

MALICIOUS

PDF

79.4 KB Created: 2021-09-10 06:47:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 806fd33d023c5e60dddc7a343d3f4ba1 SHA-1: 31cb3afd0586a4d548ed9411e03f995f6b60a1ff SHA-256: 5340a23dc012a5f50b76e4e9ef5dfa5f7cd215f30ece30adea661eacab59ba5e
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, flagging it as a phishing trojan. It contains a link farm with numerous URLs, several of which point to compromised CMS upload directories, indicating a potential distribution point for malicious content. The document body is heavily obfuscated and unreadable, suggesting it is not intended for direct user interaction but rather to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://at-studio.tw/app/webroot/userfiles/files/20210901_110717.pdf In PDF document text
    • http://tmtechvn.com/webroot/img/files/22196625864.pdfIn PDF document text
    • http://happysmilecard.com/uploads/files/momudasir.pdfIn PDF document text
    • http://iuoooo.com/filespath/files/20210908180631.pdfIn PDF document text
    • http://hometextiles-consultant.com/ckfinder/userfiles/files/52885017506.pdfIn PDF document text
    • https://burlingame.com/wysiwygfiles/file/77883358215.pdfIn PDF document text
    • http://iknow.pl/files/file/volikukubofobukakul.pdfIn PDF document text
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/oc2qi8n3f2i10s9hhsa3qgjskk/jufobosuxolakegox.pdfIn PDF document text
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/161359581e2afa---titivijej.pdfIn PDF document text
    • http://varadimasszazs.hu/uploads/files/41808271066.pdfIn PDF document text
    • http://urduhadith.org/survey/userfiles/files/fasobiresafewojakapeba.pdfIn PDF document text
    • https://csodamalom.hu/files/files/nogubigalida.pdfIn PDF document text
    • http://nattuvaartha.com/assets/ckfinder/core/connector/php/uploads/files/65209953842.pdfIn PDF document text
    • https://wotfiles.com/ckfinder/userfiles/files/loremiw.pdfIn PDF document text
    • http://reversetheclocknow.com/ckfinder/userfiles/files/41127226192.pdfIn PDF document text
    • http://www.mezmat.ru/ckfinder/userfiles/files/girejazuwegevuzol.pdfIn PDF document text
    • https://e-tta.com/app/webroot/userfiles/files/7465657691.pdfIn PDF document text
    • http://ashole.hu/UserFiles/File/29266659636.pdfIn PDF document text
    • http://sp3siemianowice.pl/userFiles/files/38435803954.pdfIn PDF document text
    • http://hoadondientu-ptp.vn/images/ckeditor/files/xixinepi.pdfIn PDF document text
    • http://www.thunderesp.com/ckfinder/ckfinder.htmlfiles/58905205353.pdfIn PDF document text
    • https://onlineadda.organicemall.com/ckfinder/userfiles/files/ruxosaginutasobexu.pdfIn PDF document text
    • http://windowsplusllc.com/ckfinder/userfiles/files/joguvipovibunifiwur.pdfIn PDF document text
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fea6974989---95312536040.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=the+wolf+of+wall+street+movie+freePDF 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_off0000ca84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA84 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e296.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE296 20076 bytes
SHA-256: 7e82f34216a06d48f28407680dd334c0d0bd04036fa84ea6af23e07e91d708c8
font_02_sfnt_off000117fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117FD 10492 bytes
SHA-256: 27e17318c0cef9064224a75acfb4271c033f1f6f3b96c368fec710b6cd54eb47

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