Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c4988f3aa9d3c73…

MALICIOUS

PDF

71.1 KB Created: 2021-09-25 12:51:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 107b6da35c78fb7d6ea53acf8eec1c07 SHA-1: f7d3f2884e4306b793cc13ee6556b42172ac37ff SHA-256: 8c4988f3aa9d3c73000a4372a98477e8b6ef507b00a53ad4a82e791356a2d7b4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery. No scripts were extracted, but the PDF structure itself is used to host these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

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://catamma.ru/uplcv?utm_term=hit+your+boss+game
    • https://www.natursany.com/ckfinder/userfiles/files/13621612689.pdf
    • http://profiklub.sanswiss.cz/files/file/69959738365.pdf
    • http://obrazyramix.pl/userfiles/file/21252240727.pdf
    • http://brianhaymore.com/images/e/file/zenakejizoxifixirudemaz.pdf
    • https://10kshot.com/customerinterview/ckfinder/userfiles/files/sasovuxejuvirewebutibifev.pdf
    • https://sayurhijau.com/contents/files/91349482637.pdf
    • https://ph2020.org/ckfinder/userfiles/files/sabibonafonebuwojilibumed.pdf
    • https://zevkotodoseme.com/upload/ckfinder/files/wezadur.pdf
    • http://monikaknoblochova.com/userfiles/file/xefawotenavevebifowowe.pdf
    • https://www.caissedesecolesdu5eme.fr/backoffice/ckfinder/userfiles/files/63165826484.pdf
    • https://wintechindia.in/ckfinder/userfiles/files/vuruduzuwikunutuwanekuvad.pdf
    • https://christianbelieversmatrimony.com/web/christiansbelieversmatrimony/photos/ckeditor/files/11290945333.pdf
    • http://liubeauty.com/luutru/files/28292872289.pdf
    • http://arabstina.com/ckfinder/userfiles/files/wukobevugidolotuv.pdf
    • http://laser-piskovani.cz/democms/userfiles/file/libakuj.pdf
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132ef5f2c250---4417671005.pdf
    • http://urs-certification.com/gais/image/file/fezak.pdf
    • http://ellev.fr/upload/files/21606639305.pdf
    • http://badgerhillfarm.uk/31769860662.pdf
    • https://bfull.ru/uploads/files/91353148082.pdf
    • https://www.pharmaright.ca/wp-content/plugins/super-forms/uploads/php/files/158f9esaanrb1d14dfsb1uhkce/71501356866.pdf
    • https://ww150002.linebot.net/upfile/files/20210904211556.pdf
    • http://ahkkpcm.org/userfiles/99421412119.pdf
    • http://www.webtony.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16145bfe32226f---83907930437.pdf
    • http://esipro.lu/userfiles/file/37920672432.pdf
    • http://royalleasingny.com/admin/images/file/rasajulexogutelaxonedikul.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_off0000b2c5.bin
ae6a4d7951964dbe580c33e755e2de0c769f8918a8a77499785a35c4892e6b7b
pdf-font-stream PDF embedded font (sfnt) at offset 0xB2C5 10644 bytes
font_01_sfnt_off0000cb40.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCB40 16792 bytes
font_02_sfnt_off0000e352.bin
99c7651c64127fbb2ae6867f8482b01c0b876de2fcfe4eee84a6d1bc0c2ae9fd
pdf-font-stream PDF embedded font (sfnt) at offset 0xE352 16436 bytes