Malicious PDF — malware analysis report

Static analysis result for SHA-256 9bc7430d252e9800…

MALICIOUS

PDF

71.4 KB Created: 2021-09-18 21:27:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: b855b3a52601a9cb173225213bbde55d SHA-1: 84943f16177fb9de4723320136e69d60e9920e3c SHA-256: 9bc7430d252e980092570ce281475b2ea64f4845027f2bd77eab34071cf9369a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to potentially compromised websites or disposable hosting. The primary purpose appears to be directing users to external, malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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.
  • 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://cmtdental.com/upload/ckimg/files/34418492101.pdf In PDF document text
    • http://sintjorisparochie.nl/userfiles/file/kamumaribadavemafe.pdfIn PDF document text
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/b97e0ee4669783691b390ae38435400f/77397535982.pdfIn PDF document text
    • https://calmoinc.com/upload/editor/file/wakapidasopuxivuleximoto.pdfIn PDF document text
    • http://ronaldtan.nl/images/photo/70125372538.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132b902abfe8---84745194696.pdfIn PDF document text
    • http://progetec.org/userfiles/files/97008719172.pdfIn PDF document text
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/6oe320s4sgbo3g4s8sp7h4npo4/niwaxabig.pdfIn PDF document text
    • http://18554080.com/userfiles/file/97105854729.pdfIn PDF document text
    • http://shop-exclusive.cz/userfiles/file/senivisoxawerufusezo.pdfIn PDF document text
    • http://vevo.keresztessyoptika.hu/elemek/file/4238751381.pdfIn PDF document text
    • http://tbff-bygg.se/img/files/90572209394.pdfIn PDF document text
    • http://cascinamana.it/userfiles/file/xosawe.pdfIn PDF document text
    • http://fence-alarm.com/userfiles/files/selubitodegojasupepogituf.pdfIn PDF document text
    • http://turbotechnik24.de/userfiles/file/rinofajorilivam.pdfIn PDF document text
    • https://bacninhonline.com/webroot/img/files/94395756353.pdfIn PDF document text
    • http://colafranceschi.it/userfiles/files/41735760012.pdfIn PDF document text
    • http://noahmission.org/dataroom/file/moponufafinenim.pdfIn PDF document text
    • http://tootingtaxi.com/survey/userfiles/files/giruf.pdfIn PDF document text
    • https://perfecthospitals.org/ckfinder/userfiles/files/93829653749.pdfIn PDF document text
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f8ebd4d882---47905482512.pdfIn PDF document text
    • http://fkjz.cn/upload/files/2021/09/202109141919172669.pdfIn PDF document text
    • https://biodent.ro/m4fm_files/m4news/ck-uploads-files/81798922005.pdfIn PDF document text
    • http://ajej.pretty-match.com/upload/files/wikadifomefami.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=friv+gta+vice+city+gamePDF 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_off0000b675.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB675 16412 bytes
SHA-256: 50b371344c91089b31cd3645b4650cae8750e413dfb24dd3aa92feb45c736812
font_01_sfnt_off0000e0ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0AB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f8c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8C2 10292 bytes
SHA-256: e303803f9e979eb85bf29b7a566722563808ffe04f382723dbf05a37ab611a54