Malicious PDF — malware analysis report

Static analysis result for SHA-256 3e97e41c0e90d6f6…

MALICIOUS

PDF

70.0 KB Created: 2021-09-24 14:31:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 352927b03fec613036ceb374d3093f20 SHA-1: a172b9a2fb796febd68b195f87f3902cbe545faa SHA-256: 3e97e41c0e90d6f60c2341dcac78ebb76247cb4956cd17066eda46bfb94dc99e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains a large number of embedded URLs, many of which point to disposable hosting and appear to be part of a link farm. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM specifically indicates this structure. While no scripts were extracted, the sheer volume of suspicious URLs suggests a phishing or redirection attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://krisoc.ru/uplcv?utm_term=onedrive+android+photo+backup PDF link annotation
    • https://sarenpinler.com/calisma2/files/uploads/pikubenuxadasutopudu.pdfIn PDF document text
    • https://www.pepinieres-gey.fr/ckfinder/userfiles/files/87902162398.pdfIn PDF document text
    • http://chandravanshi.com/userfiles/file/mokezumo.pdfIn PDF document text
    • http://slkuang.com/v15/Upload/file/202192226157722.pdfIn PDF document text
    • https://onlineadda.net/ckfinder/userfiles/files/ragiwirukefulesofujexonet.pdfIn PDF document text
    • https://newtop-eg.com/userfiles/file/nufosumo.pdfIn PDF document text
    • https://renfrewareahealthvillage.ca/ckfinder/userfiles/files/jumuwewewexi.pdfIn PDF document text
    • http://nexxosrealty.com/userfiles/files/pefanewefobuwelile.pdfIn PDF document text
    • https://inchiriereelicoptere.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613a04c2beb34---vimituwakojelibarijosebok.pdfIn PDF document text
    • http://cdenito.net/userfiles/file/raruwu.pdfIn PDF document text
    • https://manage3.realtourvision.com/rtv/ckfinder/userfiles/images/files/21039957045.pdfIn PDF document text
    • http://doggystylzgrooming.com/admin/photos/file/vimimuk.pdfIn PDF document text
    • https://elsadaulte.com/ckfinder/userfiles/files/fotagibunarufit.pdfIn PDF document text
    • http://parfumland.sk/upl/simebugakovawojelu.pdfIn PDF document text
    • https://tttinox.com/upload/userfiles/files/70884000164.pdfIn PDF document text
    • http://bk-plus.at/userfiles/files/vesonubulivaxoguganelujus.pdfIn PDF document text
    • http://2446665a.ru/ckfinder/userfiles/files/75484608223.pdfIn PDF document text
    • http://sictombbi.fr/ckfinder/userfiles/files/37704176626.pdfIn PDF document text
    • http://malagi.pl/user-files/fck/file/67888147834.pdfIn PDF document text
    • http://teamhead.net/userfiles/file/poberudovuragutotados.pdfIn PDF document text
    • https://fokusmedia.com/images/uploads/datakar.pdfIn PDF document text
    • http://hmed.vn/upload/files/kugedilogojijapekanefuxa.pdfIn PDF document text
    • http://terezmisszio.eu/files/file/33546817637.pdfIn PDF document text
    • https://vidaleve.net/ckfinder/userfiles/files/56112147004.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_off0000b051.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB051 10820 bytes
SHA-256: 4ee563fc38e2f48005e21ecafa37c5a4d586aa08c15658137836ed69c244727d
font_01_sfnt_off0000c901.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC901 16548 bytes
SHA-256: 2c9d4c55d652b113cc78cfad7eb62d7ccaff10cb62f9c6eb40922419f34138ff
font_02_sfnt_off0000f28e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF28E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1