Malicious PDF — malware analysis report

Static analysis result for SHA-256 fcf1b826c022e91f…

MALICIOUS

PDF

71.6 KB Created: 2021-09-26 15:13:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 54f78483b0b66468d082a149d1d819dc SHA-1: 19f76347e8ad513586375a33dfa0d7a8a6fbd661 SHA-256: fcf1b826c022e91fcda80a554b7b141ef8040e6ab9a1b5248e80c17da90c38bb
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to numerous external PDF files hosted on various domains, with one heuristic specifically flagging a link to an algorithmically-generated URL. The PDF's structure and embedded links suggest an attempt to distribute further malicious content or phish users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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 https://oniceh.ru/uplcv?utm_term=free+themes+and+wallpapers+for+android+phones PDF link annotation
    • http://musicincw.com/fckeditor/userfiles/image/12418450927.pdfIn PDF document text
    • https://tonthephunglan.vn/upload/files/68599482820.pdfIn PDF document text
    • http://wintec-samu.hu/uploads/files/jodibekegizevevuvotodore.pdfIn PDF document text
    • https://montpellier-business-plan.com/mbp/upload/images/images/upload/ckfinder/wowipidi.pdfIn PDF document text
    • http://rld-carbon.ru/file/2198436482.pdfIn PDF document text
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/303c24cf560ae32e0531d467c1d18c75/22269807333.pdfIn PDF document text
    • http://schokoladenfontaene.de/idata/naxoniwozutame.pdfIn PDF document text
    • http://suarezbeltran.com/aym_images/files/28144155827.pdfIn PDF document text
    • https://gujaratisamajparis.org/upload/files/54525843807.pdfIn PDF document text
    • https://psychotherapie-coeppicus.ch/userfiles/files/vaziruzafisivuredaxelom.pdfIn PDF document text
    • http://massintech.ru/img/outer/files/sekel.pdfIn PDF document text
    • http://infinity8talents.com/userfiles/file/36149173160.pdfIn PDF document text
    • http://nanouklid.cz/upload/file/6471625960.pdfIn PDF document text
    • https://estoniapools.com/contents/files/71106731122.pdfIn PDF document text
    • http://otpetye.com/images/shared/file/66463871595.pdfIn PDF document text
    • http://ambulatorioveterinariopisillibertozzi.eu/userfiles/files/57607833983.pdfIn PDF document text
    • http://rtm-plus.com/ckfinder/userfiles/files/pomitowepavi.pdfIn PDF document text
    • http://anpo.vn/upload/files/xelinozuvavuzepoluxe.pdfIn PDF document text
    • http://tianfonmm.com/d/files/manuj.pdfIn PDF document text
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614685a83a350---25802423938.pdfIn PDF document text
    • https://go2germany.ru/files/file/biraxekozudisodakaxaka.pdfIn PDF document text
    • http://cee1968.com/ckfinder/userfiles/files/40955161762.pdfIn PDF document text
    • http://hausdergesundheit.net/userfiles/files/lemolubuvikavulosuse.pdfIn PDF document text
    • https://self-storage.sg/images/uploadedimages/file/fevudador.pdfIn PDF document text
    • http://homearcky.nl/userfiles/file/busirapudawinibakanizivub.pdfIn PDF document text
    • https://hogozaty.com/ckfinder/userfiles/files/batereb.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_off0000b474.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB474 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cc8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC8B 10828 bytes
SHA-256: 1ae0ed225c4736cd2e8af11f7e449fa94a9e7d75049f47ab154118da791b76c2
font_02_sfnt_off0000e557.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE557 16140 bytes
SHA-256: 46d1800bdff0f6b9a55b3f1bf044bbca854f5a705b156e8fc49ea82f08e212be