Malicious PDF — malware analysis report

Static analysis result for SHA-256 66c7b6f12e56036f…

MALICIOUS

PDF

80.8 KB Created: 2021-09-17 18:17:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 9250a268eab92622814509438b55f893 SHA-1: b9ae26f8d192ddf927916602c52839778b9094d0 SHA-256: 66c7b6f12e56036fa39c4caee2fc2266be41a977050d6becc1cc68624ce291d7
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and multiple external URIs, with a critical ClamAV detection indicating malicious intent. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests a tactic to obscure malicious links, and the presence of a 'download button' heuristic further supports a lure-based attack. The embedded JavaScript likely facilitates the download and execution of a second-stage payload from one of the provided URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://reversetheclocknow.com/ckfinder/userfiles/files/93349770300.pdf In PDF document text
    • http://ramseier-appenzell.ch/elrada/js/ckfinder/userfiles/files/dixekanizamibom.pdfIn PDF document text
    • http://quocteanviet.com/img-chamthi/files/4796475216.pdfIn PDF document text
    • https://vegastel.eu/components/com_mijoshop/opencart/image/data/files/pumipup.pdfIn PDF document text
    • http://rafaelokazakov.com/file/lawixoguwibaxotegunelotul.pdfIn PDF document text
    • https://www.hermanosvalerorecio.com/ckfinder/userfiles/files/kufeguxaxebusiv.pdfIn PDF document text
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161320086b2706---sumitivataxutininavaxadib.pdfIn PDF document text
    • http://xn--vb0b83rba554gca.kr/page_data/file/20210908172754.pdfIn PDF document text
    • http://kingsauto-bar.com/js/upload/files/55959447414.pdfIn PDF document text
    • https://decoveinvestment.com/userfiles/file/ranifulugawaruvunubotika.pdfIn PDF document text
    • http://engineersclasses4competition.com/files/others/dukepivajozesalefa.pdfIn PDF document text
    • http://polaryachtmanufactory.com/res/wysiwyg/file/31889412413.pdfIn PDF document text
    • http://le383.com/uploads/files/88031204810.pdfIn PDF document text
    • http://sonhanint.com/uploadpic/sun/files/202109021929513444.pdfIn PDF document text
    • http://toyotarent.kr/FileData/ckfinder/files/20210907_E70C21714C837689.pdfIn PDF document text
    • https://jaurrieta.net/USERFILES_JAURRIETA/files/wufimaveredavo.pdfIn PDF document text
    • http://astorandblack.net/emailer/userfiles/file/32892057014.pdfIn PDF document text
    • http://wxmx.cn/upload/ckimg/files/202109170704376759.pdfIn PDF document text
    • http://geredekombiservisi.com/userfiles/file/69803728099.pdfIn PDF document text
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/16130acf397963---96646355106.pdfIn PDF document text
    • http://bsl-trans.ru/admin/ckfinder/userfiles/files/dakaludumibegaf.pdfIn PDF document text
    • http://greenearthgardens.org/userfiles/dajufuzinokufigavimu.pdfIn PDF document text
    • https://hirurgija.me/files/5921737416.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=puffin+web+browser+android+tvPDF 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_off0000d6b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6B5 17788 bytes
SHA-256: 6face1ec45a637fac87ee0668392435005c6387195cebd8bb192f98c2297eb6a
font_01_sfnt_off000104bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104BD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011cd4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CD4 10692 bytes
SHA-256: c5eefadef4c9c5104032e5bc05e5d49824400523c60019132fa587845ebd4c40