Malicious PDF — malware analysis report

Static analysis result for SHA-256 27f528939cd8b872…

MALICIOUS

PDF

69.9 KB Created: 2021-09-17 14:02:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 76e9f1da33424ba1c59af5a2932af54e SHA-1: c02251ad283e89134d2f19a6005662e194d8f8a5 SHA-256: 27f528939cd8b872db8e1769825cea067ed5c3d5363474876ea12e8fa934f400
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The presence of numerous embedded URLs, many hosted on disposable domains, strongly suggests a phishing or malware distribution campaign. The document body is heavily obfuscated and contains no readable text, further supporting the malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://catamma.ru/uplcv?utm_term=ball+sort+puzzle+no+ads+apk PDF link annotation
    • http://a1climbing.com/userfiles/files/61724845355.pdfIn PDF document text
    • http://studioagm.it/userfiles/files/tepedusexepir.pdfIn PDF document text
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a7b28893e3---kotalupoweguwo.pdfIn PDF document text
    • http://rapet.hu/files/1310417469.pdfIn PDF document text
    • http://lg-palette.com/upload/files/xoripugifaduseb.pdfIn PDF document text
    • https://aradovan.com/userfiles/file/zosaronulofijozo.pdfIn PDF document text
    • http://cobmedia.hu/include/kiwobesarunarosikagajerex.pdfIn PDF document text
    • http://wsm.hk/images/uploadfiles/file/nifonutabesiledejupik.pdfIn PDF document text
    • https://namdolove.com/FileData/ckfinder/files/20210902_1DD8E005304395C3.pdfIn PDF document text
    • http://cegled.varosom.hu/userfiles/files/99164821407.pdfIn PDF document text
    • https://messianic.live/wp-content/plugins/super-forms/uploads/php/files/cd1dc6ddfbf800eafa87a05088e8c516/74306687266.pdfIn PDF document text
    • https://northwestconvention.cz/data/files/87071133595.pdfIn PDF document text
    • https://adlinefor.com/home/webagen/public_html/korn/data/file/nofaxi.pdfIn PDF document text
    • http://anpharma.net/upload/files/kivavizigututijikawam.pdfIn PDF document text
    • http://carrollcountylawyers.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/lenopevepagikofotemi.pdfIn PDF document text
    • http://www.beverburcht.nl/upload/files/75576456577.pdfIn PDF document text
    • http://debnine.net/UserFiles/File/zipigumarafogi.pdfIn PDF document text
    • http://aasghsflqsae.handylover.com/upload/files/73614020555.pdfIn PDF document text
    • http://xn----gtbercbfedtm3b.xn--p1ai/admin/ckfinder/userfiles/files/wetaka.pdfIn PDF document text
    • http://dobrejaja.com/Upload/file/22048067782.pdfIn PDF document text
    • https://receptabc.hu/images_banner/files/69683138081.pdfIn PDF document text
    • http://restauraceeverest.cz/userfiles/file/8297160856.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_off0000b0ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0EC 10600 bytes
SHA-256: b82ebc3a1b1708a70cfbc40e960469e5797dd2a3a5ce7b2208edd5c547f7a3e4
font_01_sfnt_off0000c968.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC968 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e17a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE17A 15836 bytes
SHA-256: ed00d2c299be01e72c1317874685d3f47efc61cdc9253a0b9bb85963ca7d658d