Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef5c9391991b5357…

MALICIOUS

PDF

106.6 KB Created: 2021-09-21 11:13:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 5bf022334f06415f085e2566d53a9b4e SHA-1: 3f8eed74f73464f47cfaec6ec339ceefb4c8cc75 SHA-256: ef5c9391991b53576b84246772d2bd20e8fa597d5efd798041847b5556820727
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 malicious PDFs. The PDF also acts as a link farm, directing users to numerous external URLs, many of which are hosted on disposable domains. This behavior strongly suggests an attempt to redirect users to malicious sites for phishing or to download further malware. The ML classifier and ClamAV detection further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9967

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
  • 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 http://aromamahabaleshwar.com/ckfinder/userfiles/files/16024611404.pdf In PDF document text
    • https://www.osteopathe-montpellier-sud.fr/ckfinder/userfiles/files/67219754267.pdfIn PDF document text
    • http://4226080.kad.tw/kads/ckfinder/userfiles/files/tezededalumegupolakiwi.pdfIn PDF document text
    • http://florylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/29835739910.pdfIn PDF document text
    • http://beiwendq.com/data/attachment/file/61404943475.pdfIn PDF document text
    • https://lederstuhlshop.de/ckfinder/userfiles/files/natawinabebowal.pdfIn PDF document text
    • http://dogable.de/userfiles/file/94267079819.pdfIn PDF document text
    • http://oralrem.kz/ckfinder/userfiles/files/80881647890.pdfIn PDF document text
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/oanddtqsceog8hqou57u1gur1j/pifum.pdfIn PDF document text
    • https://www.travelknowhowscotland.co.uk/assets/js/ckfinder/userfiles/files/lufojebirorinilasuzakab.pdfIn PDF document text
    • http://www.emporiocaritaspisa.it/wordpress/wp-content/plugins/formcraft/file-upload/server/content/files/16136a3bf2ff98---92154925069.pdfIn PDF document text
    • http://adria-ex.com/images/blog/file/88591259560.pdfIn PDF document text
    • http://teaterskolen-efteruddannelsen.dk/ckfinder/userfiles/files/jewuwogegavetibiwukejefa.pdfIn PDF document text
    • https://iieng.org/editor/ckfinder/userfiles/files/93597512066.pdfIn PDF document text
    • http://smflow.in/admin/uploads/file/10999946226.pdfIn PDF document text
    • https://balajitutorial.com/admin/userfiles/file/kefudesifusuxuvusumeramo.pdfIn PDF document text
    • http://thucphamchucnangmy.vn/uploads/files/50541538516.pdfIn PDF document text
    • https://peltonfell.org.uk/ckfinder/userfiles/files/puwakogisivamoneki.pdfIn PDF document text
    • http://tjjjsh.com/uploads/files/38703152715.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e17c0e2a66---xumokukipovareratezo.pdfIn PDF document text
    • https://tktravelkorea.com/FileData/ckfinder/files/20210909_E8949F6D2DCEBA0A.pdfIn PDF document text
    • http://reclameindex.nl/images/uploads/96822248147.pdfIn PDF document text
    • http://jts-electrical.co.uk/ckfinder/userfiles/files/xafuwamudoteteda.pdfIn PDF document text
    • http://madmojo.com/fckupload/file/zusod.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=mirzapur+season+1+fullPDF 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_off00013e70.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E70 17972 bytes
SHA-256: 2fd45e5c75ddc9cfb32a7110402a88d9c875b9ca65ff62c9ced311657f92b807
font_01_sfnt_off00016cdc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16CDC 10460 bytes
SHA-256: d38f133f24afb54b5fd307600f9aa575259753bb2c111e8d60ecfeb29bf74992
font_02_sfnt_off000184cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x184CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1