Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b91607c8dd119dd…

MALICIOUS

PDF

69.5 KB Created: 2021-09-11 18:01:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 0df72f4dd1891ad216599c61ade5bce6 SHA-1: 9bced8d786647d264dc5594033527124eb98a4ee SHA-256: 3b91607c8dd119dd0fc2936283942411d5a1803b295caa20832139ce0cc6a50a
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous links pointing to various domains, with several heuristics flagging it as a link farm, potentially for SEO poisoning or to host malicious content. The presence of external URIs and a compromised CMS upload link further supports this. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://heathrowairporttaxi.website/userfiles/file/tefusamewuzor.pdf In PDF document text
    • http://allycatering.com/userfiles/97242140611.pdfIn PDF document text
    • http://hotechike.com/files/files/92197336331.pdfIn PDF document text
    • http://kasargod.net/uploads/file/fepoferezorif.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613916689eaa2---fapopixivetaxowogikilu.pdfIn PDF document text
    • http://tauroconsulting.pl/userfiles/file/tumusemifaw.pdfIn PDF document text
    • http://yourhandmadeitems.com/userfiles/file/35175229166.pdfIn PDF document text
    • https://shunnasato.com/13175976789.pdfIn PDF document text
    • http://studionegro.net/userfiles/files/wodosetapideduwad.pdfIn PDF document text
    • https://tssch.in/tssch/application/admin/uploads/file/semewuranaxurekibekilu.pdfIn PDF document text
    • http://yonseri.org/userfiles/files/datimokofulelisagebu.pdfIn PDF document text
    • http://coutleelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/80070497652.pdfIn PDF document text
    • http://vimar.ua/userfiles/files/1548443865.pdfIn PDF document text
    • https://curtain.jinware.com/upload/files/37371002192.pdfIn PDF document text
    • https://opescom-store.com/uploads/FCK_files/file/botisipefuwijave.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613446265f06e---61773185355.pdfIn PDF document text
    • http://matsusushionline.com/uploads/files/gexuloxobirunibileto.pdfIn PDF document text
    • https://egf.tw/test2/images/file/62849349779.pdfIn PDF document text
    • http://proximeo.com/ckfinder/userfiles/files/77899967457.pdfIn PDF document text
    • https://terminarz.online/kosmetyczka/krakow/files/jotozob.pdfIn PDF document text
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/48e86183b718c23648e1b972cb5b27de/78843915378.pdfIn PDF document text
    • http://jedzenie365.pl/ckfinder/userfiles/files/komiwososelab.pdfIn PDF document text
    • https://skvely-kup.cz/files/file/83248025088.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=panfilov%27s+28+full+movie+online+englishPDF 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_off0000af59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF59 15504 bytes
SHA-256: db31265deb458bc728f40de95e6e7a493a9a1272478efdb299b6516f8f6129a7
font_01_sfnt_off0000d706.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD706 10992 bytes
SHA-256: 0bb6676210d1bd07906ef2998fb5f71b1c7f6bdbd48e0ba146caa633091da564
font_02_sfnt_off0000f07d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF07D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1