Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf4b1d2cfee96f4a…

MALICIOUS

PDF

85.0 KB Created: 2021-09-21 01:06:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 71bd1a1fe796d41c189de579cb84003f SHA-1: 600449a8be5515253125c164dbf46be6e04e72d9 SHA-256: cf4b1d2cfee96f4a834e5935e714bd4ad8f6df525810532205ceedb1db5a6d21
126 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and the presence of numerous embedded URLs suggest the document's primary purpose is to redirect users to a collection of other PDFs, potentially for SEO poisoning or to host further malicious content. No scripts were extracted, but the structure points towards a phishing or content-luring attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • 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.
  • 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://vector-luczak.pl/new/fck_user_files/file/bowos.pdf In PDF document text
    • http://indigobaby.eu/upload/files/95068730025.pdfIn PDF document text
    • http://tiendanatacion.com/noticias/files/fujepitinuz.pdfIn PDF document text
    • https://oncetrabzon.com/resimler/files/fivexaxuxevetu.pdfIn PDF document text
    • https://eurotig.ro/file/warifa.pdfIn PDF document text
    • http://jandebruijn.com/uploadimages/files/mulikubulafodumepap.pdfIn PDF document text
    • http://enovosti.info/ckfinder/userfiles/files/wezotagifo.pdfIn PDF document text
    • http://imobiliariaimperio.com/files/files/86832014364.pdfIn PDF document text
    • http://cukiernia.eu/upload/files/letedav.pdfIn PDF document text
    • http://zeroseistudio.eu/userfiles/files/59641255388.pdfIn PDF document text
    • http://liyangah.com/Upload/file/25301621356.pdfIn PDF document text
    • http://spielundlicht.de/content_provider/documents/files/47621152009.pdfIn PDF document text
    • http://op-gold.com/ck_image/files/gukilomazupilivanusut.pdfIn PDF document text
    • http://1night2day.com/ckupload/files/kigirebopevo.pdfIn PDF document text
    • http://edu-soft.ru/site/htmlimages/file/pikeledekagakabik.pdfIn PDF document text
    • http://www.emporiocaritaspisa.it/wordpress/wp-content/plugins/formcraft/file-upload/server/content/files/16135f3c59ab26---fidukinu.pdfIn PDF document text
    • http://finalbrand.cz/upload/file/kajexisebirolejarawixun.pdfIn PDF document text
    • http://brukikostka.pl/uploads/page/file/suwogowosazevazewasaw.pdfIn PDF document text
    • https://wspaperbag.com/userfiles/file/putidex.pdfIn PDF document text
    • http://medigroupvn.com/upload/files/84570968002.pdfIn PDF document text
    • https://congnghiepxd204.vn/upload/files/raboviviloteposekomevu.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e7d633ef95---67391591125.pdfIn PDF document text
    • https://toptenstudy.com/upload/files/BodyFile__61421CFFA1B7A.pdfIn PDF document text
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files/jivaruno.pdfIn PDF document text
    • http://avandcie-automation.com/ckfinder/userfiles/files/84423910390.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=vidmate+apk+new+version+2019PDF 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_off0000e549.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE549 11180 bytes
SHA-256: 1d194f7c8cba5231db64a08d16110e029f4cda1bb15e935edd08c23a870471c3
font_01_sfnt_off0000ff8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF8E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000117a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117A0 17820 bytes
SHA-256: bb8c30bec78fb49ccb69c845e8cdc36a1b97a9c8b738a7aa697d0827275604cf