Malicious PDF — malware analysis report

Static analysis result for SHA-256 9b8095074e456878…

MALICIOUS

PDF

78.1 KB Created: 2021-09-08 16:32:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 0c0c0fcbfd16f6c02cd64cc4e1f8f097 SHA-1: d690610ea51e82234491c965cc01f2c98ad1e15e SHA-256: 9b8095074e456878e597f03e2af35ed4438fc941e0e7d22b1be8e5c778850001
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many pointing to compromised or disposable domains, indicative of a link farm designed to redirect users. Heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest a malicious intent to lure users to potentially harmful sites. The ML classifier and ClamAV detection further corroborate the malicious nature of this PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://synerhu.ru/uplcv?utm_term=prefix+and+suffix+worksheets+for+grade+5+with+answers PDF link annotation
    • http://tpt.taipei/asset/uploads/files/20921740217.pdfIn PDF document text
    • https://cezartravel.hu/userfiles/file/kinuvirexavejerezomigu.pdfIn PDF document text
    • http://hiniceshine.com/upload/65377141504.pdfIn PDF document text
    • http://mudrkanuch.sk/editor_uploads/system/files/49577002845.pdfIn PDF document text
    • http://de-ko-gmbh.com/ckfinder/userfiles/files/nulakuxijusepajapusezeru.pdfIn PDF document text
    • http://neoneophytou.com/ckfinder/userfiles/files/76057215029.pdfIn PDF document text
    • http://studiomalpocher.it/userfiles/files/71901265094.pdfIn PDF document text
    • http://brunagabriele.it/userfiles/files/34654654342.pdfIn PDF document text
    • http://hongdacable.com/d/files/masekikepinefivanuxovivip.pdfIn PDF document text
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files/wusivuzatewu.pdfIn PDF document text
    • https://publicbridge.pl/userfiles/file/53627411092.pdfIn PDF document text
    • http://yjeverspeed.com/userfiles/file/parabirupisamujakagipala.pdfIn PDF document text
    • https://forexinc.ca/upload/editor/file/53046029220.pdfIn PDF document text
    • http://idominjazz.com/fckeditor/userfiles/image/lejoxunirosiwerotowago.pdfIn PDF document text
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/6b84ceddfb7daf17022efaadb3f1f902/lipepu.pdfIn PDF document text
    • http://smartwealthhk.com/userfiles/74539482061.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133991e9ab1e---vovudagateru.pdfIn PDF document text
    • http://najlepsietorty.sk/uploads/fck/file/11596717245.pdfIn PDF document text
    • https://aprilboya.com/userfiles/file/63930657110.pdfIn PDF document text
    • http://minhnguyenvn.com/uploads/userfiles/file/38295799426.pdfIn PDF document text
    • https://houstoncoinshow.org/FCKeditor/file/21086580675.pdfIn PDF document text
    • http://mimarathi.live/assets/ckfinder/core/connector/php/uploads/files/pasutufapuguxe.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_off0000cb94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB94 17328 bytes
SHA-256: 05be0bac2a980980d7423c0b0554d7c1bccf785a371d35d87acd1a182a04e83d
font_01_sfnt_off0000f89f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF89F 11104 bytes
SHA-256: 66286446c64f3e8d4e6a11cb85287c141457c6b3dbf3c1f5d79e2528375cfb7d
font_02_sfnt_off00011263.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11263 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1