Malicious PDF — malware analysis report

Static analysis result for SHA-256 71b54cbb36c37817…

MALICIOUS

PDF

81.0 KB Created: 2021-09-17 01:56:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5c411342bdec21894e0ba9228b110ca1 SHA-1: 4dfa8cefcd6c78b0bbcf0c488c662cdb5b0a4a05 SHA-256: 71b54cbb36c3781783e1c90b0625283bcc511e3cb27b7476b52baecc183aac2f
134 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as 'Pdf.Phishing.Trojan' and an ML classifier indicated a high probability of maliciousness. It contains numerous embedded URLs, with one heuristic specifically identifying it as a link farm on disposable hosting. While no scripts were explicitly extracted, the presence of external URIs and the overall detection suggest a phishing or malware distribution attempt, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

Heuristics 6

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://churchontherockuk.org/home/churchontherock1/public_html/userfiles/files/penilowomosoweb.pdf
    • http://thomas-zigon.de/images/file/5005651603.pdf
    • http://dvif.fr/userfiles/file/64839568120.pdf
    • http://gfk-schwimmbad.de/i/File/67221449751.pdf
    • http://www.sm.ac.th/ckfinder/userfiles/files/38836936248.pdf
    • http://cukiernia.eu/upload/files/20890584286.pdf
    • http://avandcie-automation.com/ckfinder/userfiles/files/74384672681.pdf
    • http://parateam.cz/file/62286529618.pdf
    • http://uran-berlin.com/userfiles/file/5489191179.pdf
    • http://sahcarpets.com/userfiles/file/51979311487.pdf
    • http://pegastelco.com/pictures/files/xetolepadakepusedaxepep.pdf
    • http://elfuklid.cz/foto/Image/file/zemolotolusejenifodag.pdf
    • http://hauptlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/xukojitimomelopojafuw.pdf
    • https://ipekyolumedya.com/resim_galeri/file/98521173925.pdf
    • http://keramann.ru/uploads/files/27330635944.pdf
    • http://rotarycochinharbour.org/ci/userfiles/files/45752481122.pdf
    • http://www.temaricerca.com/entry2013/admin/ckfinder/userfiles/files/rurarizonifaxozexe.pdf
    • http://officinedesign.it/userfiles/files/29917148606.pdf
    • http://weorderfood.com/uploads/files/85460854680.pdf
    • http://sanmorales.es/userfiles/files/bopedirawulutupenob.pdf
    • http://jinruily.com/UploadFile/file/20210909165549052.pdf
    • http://shinaval.ru/userfiles/file/49281069035.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=bypass+launcher+apk
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ba16.bin
b7b25efa794a12d357def1e813b638a0c9db0bc5b9a19364d1a7c77ddbcfbfdc		 pdf-font-stream PDF embedded font (sfnt) at offset 0xBA16 20872 bytes
font_01_sfnt_off0000ee4c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1		 pdf-font-stream PDF embedded font (sfnt) at offset 0xEE4C 16792 bytes
font_02_sfnt_off0001065d.bin
af293b2b60dc5e826b00d8953dd18f37a59bdd939ad7d7593537948814e7f124		 pdf-font-stream PDF embedded font (sfnt) at offset 0x1065D 16232 bytes
font_03_sfnt_off00011c1f.bin
b21439a1925c7b57c66b123386be89569a0b9716c534efb0677b2c724af174da		 pdf-font-stream PDF embedded font (sfnt) at offset 0x11C1F 10520 bytes

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