Malicious PDF — malware analysis report

Static analysis result for SHA-256 6b334fbd49c7b810…

MALICIOUS

PDF

68.8 KB Created: 2021-10-02 11:05:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 335e8ac714275c1d72ee891ed8d15a4b SHA-1: 3be08d691d23ea2612dda390098ff16da47521be SHA-256: 6b334fbd49c7b8109c7c2619ef13db5736f69414129a8dd2faa365d4a2a4a1b9
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains an embedded JavaScript stream and a large number of external URIs, many of which are hosted on potentially disposable domains. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a link farm strategy, suggesting the document's primary purpose is to redirect users to malicious sites, likely for phishing or to download further malware. The embedded JavaScript may be used to facilitate this redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://meble-tk.pl/userfiles/file/7598555590.pdf In PDF document text
    • https://madeirashopping.com/userfiles/file/xidifulutokaberugimab.pdfIn PDF document text
    • https://sportnazona.bg/f/uploads/files/zixukalorawed.pdfIn PDF document text
    • http://w3-japan.com/js/upload/files/67438357910.pdfIn PDF document text
    • https://prosaison.fr/userfiles/files/puxukovibenamuzibiname.pdfIn PDF document text
    • https://www.campacinter.com/image/upload/File/fezemufasutod.pdfIn PDF document text
    • https://grandegroup.net/files/65144967532.pdfIn PDF document text
    • http://nieruchomosci-swidnica.pl/userfiles/file/7985755044.pdfIn PDF document text
    • https://apz-arte.com/ckfinder/userfiles/files/22367196954.pdfIn PDF document text
    • http://audiencefertilization.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/dimukezak.pdfIn PDF document text
    • https://excore.hu/ckfinder/userfiles/files/22147190881.pdfIn PDF document text
    • http://bc-arman.kz/ckfinder/userfiles/files/ledegatamipuzakixaliwa.pdfIn PDF document text
    • http://ventexevent.se/uploads/file/zuwusiwujugipu.pdfIn PDF document text
    • https://bokaichenyu.com/upload/files/zejagudefa.pdfIn PDF document text
    • http://interfacetravels.com/app/webroot/js/ckfinder/userfiles/files/fobanipofebob.pdfIn PDF document text
    • https://webshopplus.nl/app/webroot/files/userfiles/files/wusuwekufabobawise.pdfIn PDF document text
    • http://kezheng.net/Upload/file/zunipepijaviwinafenaje.pdfIn PDF document text
    • http://archpiudue.com/userfiles/files/76596689181.pdfIn PDF document text
    • https://tabularasa.lv/sites/tabularasa/uploads/documents/files/82457039696.pdfIn PDF document text
    • https://www.netcorp.hu/data/editorfile/18955602427.pdfIn PDF document text
    • http://self119.net/upload/userfiles/2021/09/files/210905195914.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f49a1543b6---49371873470.pdfIn PDF document text
    • https://greenboo.vn/uploads/files/26994127777.pdfIn PDF document text
    • http://uktohabbarijamalta.com/files/file/23680659428.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=find+east+west+north+southPDF 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_off0000af6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF6C 10460 bytes
SHA-256: 2dc55c03fed4a9c741b6fb5e3a29ec199ef3892cdf531a26e58cc40220b10d49
font_01_sfnt_off0000c72c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC72C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000df3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF3E 15264 bytes
SHA-256: d44ff134f9d1fc676c9e6c393af0525be9ad83e3216de550f74afb2230cf086e