Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7d083080acf2d51…

MALICIOUS

PDF

72.0 KB Created: 2021-09-07 07:01:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 4a36fe81e6317ff6407d28ab151890e2 SHA-1: 0ffc9f5a0bbdbc78dd2602ee1dc37cb8b45217cc SHA-256: a7d083080acf2d51880b4759e412bc31763a283c2307055187acd8c3d6974a17
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to compromised WordPress upload storage, suggesting it functions as a link farm to distribute further malicious content or phish users. The PDF structure and embedded URLs point towards an exploitation attempt, likely via a spearphishing attachment, to redirect users to these compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607eb9c5e184c---41267073226.pdf In PDF document text
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/a928411a497d8937b3f19877bea20d05/57581918587.pdfIn PDF document text
    • https://inchiriereelicoptere.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a22a8e7fefb---majebixadapexikagefe.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/b4db5cc5a0cdde0734ab3130745b528f/lewopemi.pdfIn PDF document text
    • https://tonwen.org/userfiles/file/42548906133.pdfIn PDF document text
    • http://ebd.su/UFD/7623/files/monomovazajobimenuselenij.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/160a1b0f6cb73d---13772573691.pdfIn PDF document text
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c14672a21f3---8553874867.pdfIn PDF document text
    • https://stop-remont.ru/ckfinder/userfiles/files/duxipojijakaletabofulemaf.pdfIn PDF document text
    • http://foire-fromages-et-vins.com/wp-content/plugins/formcraft/file-upload/server/content/files/16100ea2a411fe---43679817046.pdfIn PDF document text
    • https://www.brightfieldbusinesshub.co.uk/wp-content/plugins/super-forms/uploads/php/files/7dma5sk7mij8gbq1u44egkah1e/woluruzef.pdfIn PDF document text
    • https://www.dishdivvy.com/wp-content/plugins/super-forms/uploads/php/files/9325f0d9fdf33c2965daa7ce9c361127/46862122046.pdfIn PDF document text
    • http://belean.pl/userfiles/file/49509551655.pdfIn PDF document text
    • http://chnli.tw/CKEdit/upload/files/4742722781.pdfIn PDF document text
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611489576c072---64722427730.pdfIn PDF document text
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/57243e9e73abfaf352c5dcac773c0f18/sadaganalo.pdfIn PDF document text
    • https://chaplains-camps.org/upload_picture/file/2687636945.pdfIn PDF document text
    • http://www.moteco.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609014d3686ba---savame.pdfIn PDF document text
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161219f2d9004a---nutixasajojim.pdfIn PDF document text
    • http://animationcoach.com/userfiles/file/mapobawanitunowepabaw.pdfIn PDF document text
    • http://familiegravesen.dk/ckfinder/userfiles/files/32712105804.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d0a6ebf4e9---modevokoga.pdfIn PDF document text
    • http://juditphotography.com/picture/userfiles/file/bonuvifamapajaxikinubenep.pdfIn PDF document text
    • http://dellalontra.it/userfiles/files/19181452517.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=crystallization+of+copper+sulphate+pdfPDF 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_off0000b983.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB983 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d195.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD195 15352 bytes
SHA-256: cec57e5954a3dcea63ba498f02932ddcd4e1c12d6eeeb4e3d8aec9f6cdd6e9e3
font_02_sfnt_off0000f858.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF858 11024 bytes
SHA-256: c83ea45de8b1e7a7e7a0e70fa4baa24bc90009dd2554362896b30ab675180df9