Malicious PDF — malware analysis report

Static analysis result for SHA-256 99716be6864e3088…

MALICIOUS

PDF

72.6 KB Created: 2021-09-27 00:29:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 6c508c497801175e0f11375355fdd9de SHA-1: 20eab9607f82428774ec63b8d62c729e67465c96 SHA-256: 99716be6864e30887cf781a41ec382fb5eabe394b2a48212c8a8c1ea563bc867
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple domains, several of which are identified as compromised WordPress upload storage or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to malicious sites for phishing or further malware delivery. No scripts were extracted, and the document body was unreadable binary data.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://merklink.nl/site/data/ws/files/14018482193.pdf In PDF document text
    • http://herbwaterthailand.com/userfiles/files/gitibijujorodowezaj.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614893430334e---gevugijipolumag.pdfIn PDF document text
    • https://xn--fiqa735be48e.com/upload/files/jixiwisuke.pdfIn PDF document text
    • http://artiguardia.pl/userfiles/file/12148858508.pdfIn PDF document text
    • https://www.baileysmilk.com/wp-content/plugins/super-forms/uploads/php/files/3c8cf4a72e7357bb0e381b94ff948772/wowonap.pdfIn PDF document text
    • https://paidionresearch.com/userfiles/files/6507373439.pdfIn PDF document text
    • http://anipetkingdom.com/webroot/img/files/4270344522.pdfIn PDF document text
    • http://www.larucheapain.fr/ljk/file/geruxivazif.pdfIn PDF document text
    • https://acrgroup.nl/userfiles/file/ratijefite.pdfIn PDF document text
    • https://receptabc.hu/images_banner/files/4041388917.pdfIn PDF document text
    • http://redemaisfarma.com/userfiles/file/76096668767.pdfIn PDF document text
    • https://mamadona.ru/ckfinder/userfiles/files/kovivomatuviribatixim.pdfIn PDF document text
    • https://calienglish.com/ckfinder/images_store/files/61881892205.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613304dc30bea---85531979707.pdfIn PDF document text
    • https://merohamro.com/ckfinder/userfiles/files/zogunikigoxevegul.pdfIn PDF document text
    • http://cutyoursupport.com/userfiles/file/75201197799.pdfIn PDF document text
    • https://efficimm.fr/userfiles/files/kidedavobu.pdfIn PDF document text
    • http://krajinar.cz/soubory/files/rivarolajobugakitaxi.pdfIn PDF document text
    • http://dobryremont.pl/ebobas/portal/app/webroot/img/tmp/file/16318315404432.pdfIn PDF document text
    • http://buyyoutubecomments.com/ci/userfiles/files/nipuk.pdfIn PDF document text
    • http://24cvety.ru/upload/files/82137917798.pdfIn PDF document text
    • http://t-p-fortune.com/userfiles/file/40137067156.pdfIn PDF document text
    • http://www.juniorcollege.cl/ckfinder/userfiles/files/maxiretitixodobuxawasedef.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=eac3+audio+is+not+supported+in+mx+playerPDF 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_off0000b2db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2DB 11148 bytes
SHA-256: 7d809e29e9ea5871e0129f37fe26743ea06fa99d1a68fb73c92d0c0e1f1707d8
font_01_sfnt_off0000ccf1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCF1 18204 bytes
SHA-256: b55be4f04994bc55ea8739e1de9ad452e6a1b0f3f41983cb52c6b6a9118c439d
font_02_sfnt_off0000fc78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC78 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1