Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ca36aca9a7f0e51…

MALICIOUS

PDF

85.5 KB Created: 2021-09-06 16:36:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: e92be61216c96342148f48c071bc2351 SHA-1: 10b3f4c2f28cddf0b4671594068eaa00bbbc5739 SHA-256: 4ca36aca9a7f0e51c7e7259b458319c5d0a9e4bc06abda7c3bcc9b6398799df8
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. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS upload storage and disposable hosting. These findings suggest the document is designed to redirect users to potentially harmful websites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://apexforestservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b43f10cf1ab---dukowuguzawox.pdf In PDF document text
    • http://abwrichmond.com/uploads/files/pafusekuwunolop.pdfIn PDF document text
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/o0svj6rhrh4e567pd40e0ap5oo/zakitebarikumowe.pdfIn PDF document text
    • http://instandee.com/Images_upload/files/50207106635.pdfIn PDF document text
    • http://websteravelandscaping.com/editorData/file/80871594817.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078d5e9eac2f---dufuzuvuvatod.pdfIn PDF document text
    • https://wemservice.com/ckfinder/userfiles/files/20823910206.pdfIn PDF document text
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092e7abbac46---75274722225.pdfIn PDF document text
    • https://sasalidayanisma.org/uploads/file/53006661298.pdfIn PDF document text
    • http://www.awakohchang.com/image/upload/File/opexolizojatun.pdfIn PDF document text
    • http://sanmorales.es/userfiles/files/80702688326.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/iic9i56k1dc04cte52e9tdsh4c/59448778543.pdfIn PDF document text
    • https://www.emma-solutions.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609fdf548be0a---bezefonunolo.pdfIn PDF document text
    • https://www.clubmanizales.com.co/wp-content/plugins/formcraft/file-upload/server/content/files/160b37557d0e15---vibuzuvomitozan.pdfIn PDF document text
    • http://soft-pro.hr/upload/datoteke/44290432961.pdfIn PDF document text
    • http://pijntherapie.be/uploads/files/bezugudoliralafaxuxijo.pdfIn PDF document text
    • https://neksav.com/upload/ckfinder/files/41659236347.pdfIn PDF document text
    • https://ystechpro.com/nbloom/fckuploads/file/sozowugifi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=logicool+ac+remote+manualPDF 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_off0000e672.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE672 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fe89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE89 10460 bytes
SHA-256: 7660b9442c08af482dfc4d23b20986a51b901edf0ce3574a54bad8c0fca49611
font_02_sfnt_off00011642.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11642 19316 bytes
SHA-256: 77836281eba6bf8043aa77233791c2d949c392c4c5f6d578b5a5e7f41bbcefb0