Malicious PDF — malware analysis report

Static analysis result for SHA-256 a85f35be7a54684a…

MALICIOUS

PDF

73.7 KB Created: 2021-09-13 09:50:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 16a27e6cc4f070ca624e62e3421dea2c SHA-1: a28e6b602830d6846f3b84fce161ac7c4a490365 SHA-256: a85f35be7a54684a2e8612420df30bf50f993ced1f4c251207cb36670d9c6575
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, suggesting a link farm used for redirection. While no executable scripts were directly extracted, the structure and URL patterns are consistent with phishing lures or malware droppers.

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://www.majbrno.cz/uploads/files/rosenukimidexegodijexuzuz.pdf In PDF document text
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ec533b7588---31651556747.pdfIn PDF document text
    • http://dansecyr.ca/pdf/file/41376591433.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161337901e2957---21889923562.pdfIn PDF document text
    • http://ijdssymposium.eu/upload/xuzizi.pdfIn PDF document text
    • https://sitycare.com/FCK-UserFiles/files/47550998670.pdfIn PDF document text
    • http://home-hj.com/up_photo/file/vofakekaj.pdfIn PDF document text
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/9jjajm8t1je8cv4ipsj57pl544/rimafosum.pdfIn PDF document text
    • https://agros.net/uploads/file/mejogepolufazefe.pdfIn PDF document text
    • http://supermarketdv.ru/files/file/gagemigere.pdfIn PDF document text
    • http://kiuruvedenlukio.fi/tiedostot/file/36668250887.pdfIn PDF document text
    • http://clear-es.net/yamituki-n/uploads/files/94884330903.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/16131835a293ad---39087459885.pdfIn PDF document text
    • https://bczenekar.hu/files/file/26384219393.pdfIn PDF document text
    • http://ryukatsu.com/userData/board/file/dosivaxaxavebuvise.pdfIn PDF document text
    • http://kammed.com/userfiles/file/68994979474.pdfIn PDF document text
    • http://www.thunderesp.com/ckfinder/ckfinder.htmlfiles/zevubuzirovubiv.pdfIn PDF document text
    • http://skene.es/userfiles/file/moxujovuni.pdfIn PDF document text
    • http://onlineticketreview.com/images/file/50083193355.pdfIn PDF document text
    • https://mangalargalux.com.br/ckfinder/userfiles/files/renosoxerexijaz.pdfIn PDF document text
    • http://metafelix.it/userfiles/files/98289795386.pdfIn PDF document text
    • http://www.uc-kushiro.net/images/library/File/41163160861.pdfIn PDF document text
    • https://davidfoleyinc.com/userfiles/file/noxapozejupoxe.pdfIn PDF document text
    • http://khaskhaan.mn/uploads/userfiles/files/11609934312.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=hack+among+us+mobile+androidPDF 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_off0000bf00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF00 16188 bytes
SHA-256: fc954dead49590f5a9b6efe9a6bebda3e760967a834aa976f3c754d12251db8e
font_01_sfnt_off0000e860.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE860 10940 bytes
SHA-256: 6b9c3735e99f51ce650d4513f9d4a3da6afaa76e106917d0f0a7412f61583bf1
font_02_sfnt_off00010171.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10171 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1