Malicious PDF — malware analysis report

Static analysis result for SHA-256 53ac40f4e87a3480…

MALICIOUS

PDF

72.6 KB Created: 2021-09-29 14:55:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 1636e0a283616f31b0d68fb68a7fa237 SHA-1: 45dca700bbe00581e52664b88c971fe63ea7a6a9 SHA-256: 53ac40f4e87a3480592a4316996f5c1d19d68a26c342b7df1950f13231001b8e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. The presence of numerous external URIs, many pointing to disposable domains and configured as a link farm, strongly suggests a phishing or malware distribution attempt. The document body is heavily obfuscated, but the PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates the document's purpose is to redirect users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 https://huntic.ru/uplcv?utm_term=dolphin+wifi+hacker+apk PDF link annotation
    • http://protezas.lt/i/File/18419532781.pdfIn PDF document text
    • http://na3.it/misc/file/saxalasomire.pdfIn PDF document text
    • http://jolanyee.com/upload/files/202109120712549253.pdfIn PDF document text
    • http://nocleginaplus.pl/uploads/userfiles/files/remev.pdfIn PDF document text
    • https://mekongtransport.com/upload/userfiles/files/43746005638.pdfIn PDF document text
    • http://yangs-ns.com/ckfinder/userfiles/files/20210902132940.pdfIn PDF document text
    • http://sosonomo.com/ckfinder/userfiles/files/73047491853.pdfIn PDF document text
    • http://oresteruggiero.com/userfiles/files/26812339815.pdfIn PDF document text
    • http://zdrowejaja.com/Upload/file/71505865605.pdfIn PDF document text
    • http://privateeducation.sg/verzsape/demo/upload/admin/files/vomutubevok.pdfIn PDF document text
    • https://shinyjewellers.com/wp-content/plugins/super-forms/uploads/php/files/6bpplckredssduc8k79dapjj1e/sadorafapazivonijoxuvuwug.pdfIn PDF document text
    • http://huynhgiabaohotel.com/uploads/FCK/file/ditizugogarawaw.pdfIn PDF document text
    • http://tbff-bygg.se/img/files/gevasigonobo.pdfIn PDF document text
    • https://seedcambodia.org/htdocs/cljr/data/files/37729591993.pdfIn PDF document text
    • http://pinxedien.net/upload/files/82165525362.pdfIn PDF document text
    • http://degeninhotel.ru/admin/ckfinder/userfiles/files/43527504088.pdfIn PDF document text
    • https://nezrenpin.com/calisma2/files/uploads/22517673129.pdfIn PDF document text
    • https://www.blondel-bois.fr/ckfinder/userfiles/files/bekolekibal.pdfIn PDF document text
    • http://scpt.it/userfiles/files/welemolipijonibibajefagud.pdfIn PDF document text
    • http://ipjanah.ir/wp-content/plugins/super-forms/uploads/php/files/6hap6d1tmb2hglhdl5t31tiusk/fejaxofemopesutilojog.pdfIn PDF document text
    • http://schokofontaene.de/idata/99675572794.pdfIn PDF document text
    • https://basundharamart.com/userfiles/file/javezelewi.pdfIn PDF document text
    • http://www.slenderclub.cz/ckfinder/userfiles/files/9835180021.pdfIn PDF document text
    • http://bkdesign.ee/userfiles/file/50892461740.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_off0000b6d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB6D6 18040 bytes
SHA-256: 97e07aa219c90d72f9a62a32adec6b9256c0665856ae0f8048dab1723e6e6c99
font_01_sfnt_off0000e4f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4F4 10492 bytes
SHA-256: 12212e4a9f7db2c5fbaa9e6f5448612ce068a9514acb30c0854497d023403474
font_02_sfnt_off0000fcc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCC3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1