Malicious PDF — malware analysis report

Static analysis result for SHA-256 23f7bff7e0946dac…

MALICIOUS

PDF

70.4 KB Created: 2021-09-26 06:23:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: c84a7829ca53d19622ecde469ca8d2f7 SHA-1: 0232572de21624a5bc74ce16c3afe41856c45d80 SHA-256: 23f7bff7e0946dac93841e3fd8f24ef23b929009dc6ea98a85064de9ee6ec04a
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for delivering malicious content. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates the document is designed to host numerous links on disposable domains, suggesting a phishing or malware distribution campaign. The ML classifier and ClamAV detection strongly support its malicious nature, likely as a phishing or trojan delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://ketchas.ru/uplcv?utm_term=the+call+of+the+wild+online PDF link annotation
    • http://akiyastyle.com/app/webroot/js/ckfinder/userfiles/files/70219206141.pdfIn PDF document text
    • http://www.prieteniitehnicii.ro/documente/file/14559632396.pdfIn PDF document text
    • https://108pizza.pl/uploads/userfiles/files/76394680553.pdfIn PDF document text
    • https://turismo-galicia.es/ckfinder/userfiles/files/sesawibuzokagusowufuj.pdfIn PDF document text
    • https://warsztatgdynia.pl/app/webroot/media/files/12675111615.pdfIn PDF document text
    • http://przedszkolenisko.pl/userfiles/file/kevarebujawuzep.pdfIn PDF document text
    • https://www.weboonline.com/ckfinder/userfiles/files/xaragumumogunusula.pdfIn PDF document text
    • http://whipitleather.com/userfiles/file/48604103080.pdfIn PDF document text
    • http://miyagi.chi-kara.net/Upload/files/16962316152.pdfIn PDF document text
    • https://ww150006.linebot.net/upfile/files/20210926085511.pdfIn PDF document text
    • http://letsfinal.com/userfiles/file/77507798504.pdfIn PDF document text
    • https://implant-drill.com/userfiles/file/bawutanepaloradi.pdfIn PDF document text
    • http://suliaok.com/v15/Upload/file/2021912720172480.pdfIn PDF document text
    • http://kaies.net/upfiles/210919202212910723ghjr06.pdfIn PDF document text
    • http://snieznik.pl/userfiles/file/dimiza.pdfIn PDF document text
    • https://newsru.md/upload/userfiles/files/3677022065.pdfIn PDF document text
    • https://viessmannboilers.ca/fck_upload/file/xagaranuxaseredijipotun.pdfIn PDF document text
    • http://bienchidan.org/uploads/files/xabipepuxonawudozu.pdfIn PDF document text
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/3129405660.pdfIn PDF document text
    • https://gloriamus.org/Uploads/userfiles/files/laxuguma.pdfIn PDF document text
    • http://www.abcklima.hu/data/editorfile/81078282090.pdfIn PDF document text
    • https://habibitours.org/ckfinder/userfiles/files/xidovinubikotusukilab.pdfIn PDF document text
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/16143db0d3b289---91368004260.pdfIn PDF document text
    • https://www.sensiblemachines.com/ckfinder/core/connector/php/files/7931111583.pdfIn PDF document text
    • 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_off0000b4b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4B1 15992 bytes
SHA-256: cefb7b0b733321827680d1c9a70cce865ef52c7887e90df101a6b828537ce14e
font_01_sfnt_off0000dc61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC61 10352 bytes
SHA-256: a2f83ea6c6f104cef3f075332914144b4d0cb5cf785fb375077f282056365b58
font_02_sfnt_off0000f3c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3C7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1