Malicious PDF — malware analysis report

Static analysis result for SHA-256 c6f5b961a78c16a9…

MALICIOUS

PDF

84.1 KB Created: 2021-09-15 20:48:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 4ca03e45b7a40ef967e329bacaaaa82b SHA-1: 7a6e854401a03660059aa5f81e34b775ed43f8ec SHA-256: c6f5b961a78c16a9489989b0772b1640059807d76f7067eaa4932a232a78f1fd
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites and disposable domains, indicating a link farm designed to lure users to external content. ClamAV and ML classifiers identified this PDF as malicious, specifically flagging it as phishing or a trojan. The presence of these links suggests an attempt to redirect users, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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 http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/f6ba2a36ed35d850483087c48c0f18bd/junoruxakowi.pdf In PDF document text
    • http://salespate.com/userfiles/file/23859989207.pdfIn PDF document text
    • http://rencontres-icare.org/userfiles/file/xigixitu.pdfIn PDF document text
    • http://crystalnymph.by/wp-content/plugins/super-forms/uploads/php/files/c31aef4d65e0753886c199099e868094/88876996081.pdfIn PDF document text
    • http://logiccpacma.com/ckfinder/userfiles/files/359172244.pdfIn PDF document text
    • http://vers-ma.de/userfiles/file/38891250675.pdfIn PDF document text
    • http://villaturri.it/wp-content/plugins/formcraft/file-upload/server/content/files/16140f42e284b6---winogikatajug.pdfIn PDF document text
    • http://centrons.com/uploaded/file/167329275561364f50f14cc.pdfIn PDF document text
    • http://ericshartman.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/98633132962.pdfIn PDF document text
    • https://optimumquestsolutions.com/ckfinder/userfiles/files/kuwusupafo.pdfIn PDF document text
    • http://smenergy.kr/uploaded/file/1605072727613de20b430b1.pdfIn PDF document text
    • https://thietbigas.net/media/files/91964487654.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/16131ada4b9ff4---1494373753.pdfIn PDF document text
    • http://tantusmarina.com/UserFiles/file/xetonoku.pdfIn PDF document text
    • http://0225674989.kad.tw/kads/ckfinder/userfiles/files/18100822730.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/vezekafu.pdfIn PDF document text
    • https://hosvagyok.hu/userfiles/file/gejipunivimibuzajebuwo.pdfIn PDF document text
    • http://maksimetall.ru/files/20770179559.pdfIn PDF document text
    • http://deeringbayrealestate.com/userfiles/files/37631266663.pdfIn PDF document text
    • http://a-aqua.fr/ressource/site-image/files/74439047579.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/161304d40de6ca---laxinapenuvisa.pdfIn PDF document text
    • https://regiefranchet.fr/userfiles/files/zapavi.pdfIn PDF document text
    • http://drcleancenter.com/uploads/files/202109120604245826.pdfIn PDF document text
    • http://thietbikhachsanvinhhung1.com/upload/files/fitekadupolijij.pdfIn PDF document text
    • https://cjsc.se/ckfinder/userfiles/files/9971592377.pdfIn PDF document text
    • https://castilloexterior.org/ckfinder/userfiles/files/zunaxakofekok.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=acelerador+de+memoria+ram+para+androidPDF 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_off0000e12d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE12D 19268 bytes
SHA-256: 31c05653e89c7910ea87dbbb8702b23dc646d16fec5b04f046749f0ebe7b4bc8
font_01_sfnt_off0001125c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1125C 10392 bytes
SHA-256: 7e7a27048533a547d0a7268853844199806957491769f04fb5ed1995b211fb1a
font_02_sfnt_off000129c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129C6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1