Malicious PDF — malware analysis report

Static analysis result for SHA-256 3efb0b0f8f0d9846…

MALICIOUS

PDF

81.4 KB Created: 2021-09-16 00:17:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 2441cf2a0dab71a25fe3faa83e448063 SHA-1: 4a0083862bec43eadf65bd68b93dd5919c45997c SHA-256: 3efb0b0f8f0d9846f6534e8e6bfe64601364465b6a903283fe8acc9ece493b21
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple heuristic firings indicating malicious intent, including random and disposable URLs, and is flagged by ML classifiers and ClamAV as a phishing trojan. The embedded URLs suggest the document acts as a lure, directing users to potentially malicious content hosted on various domains. No scripts were extracted, but the PDF structure itself is used to facilitate the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://b2b-intelligence.it/uploads/file/31817027111.pdf In PDF document text
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613406388a7b2---70424443757.pdfIn PDF document text
    • http://onlinemidias.com/ckfinder/userfiles/files/45854633565.pdfIn PDF document text
    • http://thanhnhomdinhhinh.net/uploads/files/tovadamatamazekesuxaw.pdfIn PDF document text
    • http://iccjsc.com/images/uploads/files/wurokolusaripawufifasug.pdfIn PDF document text
    • http://nmways.com/uploads/fckupload/file/68156539902.pdfIn PDF document text
    • http://beverly.kopanramen.com/uploads/files/47124140145.pdfIn PDF document text
    • https://quizai.com/uploads/files/nezadevogerogugekom.pdfIn PDF document text
    • https://kamhosting.nl/ckfinder/userfiles/files/65748827711.pdfIn PDF document text
    • http://vetranhtuong.info/luutru/files/noduxowazatusa.pdfIn PDF document text
    • http://safedoorsystems.com/cmsimages/file/luluvejorolizixoximolezi.pdfIn PDF document text
    • http://schokozentrale.de/idata/46358676631.pdfIn PDF document text
    • https://rimsball.com/ckfinder/userfiles/files/74857742745.pdfIn PDF document text
    • https://vico-real-estate.com/ckfinder/userfiles/files/23200433840.pdfIn PDF document text
    • http://paitoonbox.com/userfiles/files/21514389511.pdfIn PDF document text
    • http://rdmsrl.it/userfiles/files/regavofagubovatusisowaf.pdfIn PDF document text
    • http://amphorabeautyclub.com/campannas/file/2103973934.pdfIn PDF document text
    • http://ambulatorioveterinarioscapindandrea.it/userfiles/files/70148186783.pdfIn PDF document text
    • http://eastcoastbiker.de/sites/default/files/file/79821735098.pdfIn PDF document text
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d17ea79d18---vogijadaxofitagapa.pdfIn PDF document text
    • https://drishtinetcom.in/FCKeditor/file/lukuzusitadupukov.pdfIn PDF document text
    • http://adaviestransportltd.com/userfiles/file/90061871674.pdfIn PDF document text
    • https://balticstroy.com/uploads/files/midizi.pdfIn PDF document text
    • https://www.esicm-old.org/admin/lib/ckfinder/userfiles/files/darupanudobuwoje.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=one+side+of+chest+bigger+than+otherPDF 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_off0000d86a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD86A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f081.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF081 10872 bytes
SHA-256: 6b69b45dc177497c5eddf5f7ea877237db2db6f426bb9d465e276e5aa1f0dd80
font_02_sfnt_off00010969.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10969 17904 bytes
SHA-256: aa5606647ce72d3a5c93296253ef6886a5ad6f1202e0b09f61b6c7714aec88ae