Malicious PDF — malware analysis report

Static analysis result for SHA-256 839fa75298fa47f1…

MALICIOUS

PDF

74.6 KB Created: 2021-09-18 05:43:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: fda89cc6ad34cd529e13cb6a0d56fe28 SHA-1: ed4d41c3e00cc749ad1193cdc93a434b3a83303d SHA-256: 839fa75298fa47f1d87f63173cb76754467f2958f45118a14585976b54f66913
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm and a callback phishing lure, suggesting it directs users to potentially harmful websites. The presence of numerous embedded URLs further supports the phishing or malware distribution attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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=vehicle+sold+as+is+form+pdf PDF link annotation
    • http://4998horo.gmmwireless.com/contents/files/77869415253.pdfIn PDF document text
    • http://termosystem.pl/userfiles/file/rivutamosasulopilan.pdfIn PDF document text
    • https://habrit.tw/ckfinder/userfiles/files/vidifigosoxefalowu.pdfIn PDF document text
    • http://adaviestransportltd.com/userfiles/file/90061871674.pdfIn PDF document text
    • http://zkojicin.cz/userfiles/file/67272941281.pdfIn PDF document text
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161446623a6816---74309760102.pdfIn PDF document text
    • https://balbok.net/admin/ckfinder/userfiles/files/jepejukamerafewisazome.pdfIn PDF document text
    • http://aceonlinementors.com/userfiles/file/segivilabomiro.pdfIn PDF document text
    • https://www.mftelhas.com.br/adm/Editor/ckfinder/userfiles/files/65253769169.pdfIn PDF document text
    • http://mamnonhieutrung.edu.vn/ckfinder/userfiles/files/jumuwojol.pdfIn PDF document text
    • http://hotechike.com/files/files/tikagutegojezuvisetizonud.pdfIn PDF document text
    • http://rem-proekt.com/f/file/keguwi.pdfIn PDF document text
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/1613a5aa014758---28729387428.pdfIn PDF document text
    • http://sujitonweb.com/userfiles/files/31211547562.pdfIn PDF document text
    • https://sevenhillsgroup.net/ckfinder/userfiles/files/2918737293.pdfIn PDF document text
    • https://33mobility.net/uploads/files/35457150149.pdfIn PDF document text
    • http://chothuexehochiminh.com/userfiles/file/xukipokajuromiz.pdfIn PDF document text
    • https://jsptti.com/ckeditor/ckfinder/userfiles/files/dawulupikatitoroxedixuxit.pdfIn PDF document text
    • http://kustari.net/userfiles/file/6812762908.pdfIn PDF document text
    • http://asckhn.com/acskhn/userfiles/file/volezuva.pdfIn PDF document text
    • http://www.alliance-bio.com/user_data/editor/ckfinder/core/connector/php/upload/files/1491016302.pdfIn PDF document text
    • https://gentrilieu.vn/userfiles/file/larudinaran.pdfIn PDF document text
    • http://wumag.pl/userfiles/file/sigajobitarowibo.pdfIn PDF document text
    • http://myoffice2561.sesao33.net/UserFiles/File/newumimuzuvozamipo.pdfIn PDF document text
    • http://jewelry-shopping-city.com/uploads/files/202109161227098450.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_off0000c1c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1C2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d9d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9D9 10652 bytes
SHA-256: 859bab957f49ae6e844274ac64678ac1225ef003988cdb1ac7d136a23d8d0a15
font_02_sfnt_off0000f23a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF23A 16548 bytes
SHA-256: 39672f0e7b286d6d0cdbdf94ff703d040529c47de4730d889c6828309d9b94d4