Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4d057f18c9ebb23…

MALICIOUS

PDF

82.8 KB Created: 2021-09-12 20:04:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 7df7f71cf035443611de93e90a7d2e7c SHA-1: a6819b0554420b1d07067bee4f3b48d640b9ff7f SHA-256: d4d057f18c9ebb23899da8adbecefba967fac18492b2841f6278314c5d970f94
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a large number of external URIs, many of which are hosted on disposable domains and appear to be part of a link farm. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware distribution via these links. The embedded JavaScript is likely used to facilitate the redirection or obfuscate the malicious links.

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://lhdrum.com/User_File/UpFile/file/20210901160405_OTUyNDEzNzM1NDA=.pdf In PDF document text
    • http://oa30us.com/userfiles/file/sowivogukuxewozota.pdfIn PDF document text
    • http://gyarmatilovastorna.hu/userfiles/file/vijekigudutogalisuj.pdfIn PDF document text
    • http://ecohost.ru/pics/images/file/16886289599.pdfIn PDF document text
    • https://alihuata.com/userfiles/file/7812770845.pdfIn PDF document text
    • http://aotwcasino.com/ckfinder/userfiles/files/91425097568.pdfIn PDF document text
    • http://vuonlan.vn/data/upload/files/35851499377.pdfIn PDF document text
    • https://chsins.tw/uploads/files/202109052121238570.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131155146e08---gaminexudu.pdfIn PDF document text
    • http://www.stsmcc.org/www/js/ckfinder/userfiles/files/nabajegamolibaxuzadope.pdfIn PDF document text
    • https://vsevolozhsk.mebel18.com/uploads/files/wevoderirodita.pdfIn PDF document text
    • https://leciv.fr/uploads/FCK_files/file/7606544334.pdfIn PDF document text
    • https://feniks9.ru/ckfinder/userfiles/files/fimunep.pdfIn PDF document text
    • http://awkontrakt.pl/ckfinder/userfiles/files/22173983325.pdfIn PDF document text
    • http://border-collie.ru/sites/default/files/file/topomexujopop.pdfIn PDF document text
    • http://pkpneu.cz/userfiles/file/rodunozanapo.pdfIn PDF document text
    • https://diamond-marketing.cz/soubory/32313252474.pdfIn PDF document text
    • http://www.facyt.com.ar/ckfinder/userfiles/files/98491029073.pdfIn PDF document text
    • https://kentacademymiango.com/userfiles/file/29333856070.pdfIn PDF document text
    • https://osiindia.org/ckfinder/userfiles/files/5508783950.pdfIn PDF document text
    • https://nezamirekhaseafoods.com/userfiles/file/55300340119.pdfIn PDF document text
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613d7c3226a5a---nizibami.pdfIn PDF document text
    • http://techsystem.gr/data/uploads/ckeditor/files/69231926366.pdfIn PDF document text
    • http://greddy.com/admin/common/ckfinder/userfiles/File/54476694434.pdfIn PDF document text
    • https://maintogelonline2.bet/contents/files/58269285015.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=convert+multiple+excel+sheets+to+pdf+onlinePDF 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_off0000dd58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD58 11024 bytes
SHA-256: 2b3b91485e8fd52179fe2ffdf9292716b86ebfc5b275dd55ae5510938f2a46ce
font_01_sfnt_off0000f6cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6CB 18044 bytes
SHA-256: f9cdcd25bfff6f02333cbd31dfa8530ad42689110bd68e57b0433c8c205371c4
font_02_sfnt_off0001259c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1259C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1