Malicious PDF — malware analysis report

Static analysis result for SHA-256 a36810885463af27…

MALICIOUS

PDF

97.5 KB Created: 2021-09-04 09:46:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 841957a89111cce469b4500483878caf SHA-1: 148209860c26d412c292be984c98f91ccef4ce3d SHA-256: a36810885463af278a2b16f8f11f570ac46730cb492ab45a255d13e82402d59f
156 Risk Score

Malware Insights

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

The sample is a PDF file flagged by multiple heuristics and a machine learning classifier as malicious. It contains numerous links pointing to compromised WordPress upload directories and other disposable hosting, suggesting a link farm designed to redirect users. The ClamAV detection as 'Pdf.Phishing.Trojan' further supports its malicious nature. The primary attack pattern involves leveraging these links to deliver a secondary payload or redirect users to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://livingcircles.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1606e60916f84e---35860054904.pdf In PDF document text
    • http://tatugigo.com/ckfinder/userfiles/files/78888978733.pdfIn PDF document text
    • http://www.celso.org/download/nedebuduxum.pdfIn PDF document text
    • https://www.southdownscellars.co.uk/ckfinder/userfiles/files/dakisiresaditemakib.pdfIn PDF document text
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/5761ac289699d9d29a285de5641103d9/68690711450.pdfIn PDF document text
    • http://steakclubhn.com/campannas/file/96738319255.pdfIn PDF document text
    • http://stolizstekla.ru/userfiles/file/50560252434.pdfIn PDF document text
    • https://ecohort.com/userfiles/files/derifezonakusigozopuka.pdfIn PDF document text
    • http://ansing.nl/userfiles/file/titisisixujewazogizafuzu.pdfIn PDF document text
    • https://moveo-sport.pl/userfiles/file/tunifevomave.pdfIn PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609039fec848a---xozovip.pdfIn PDF document text
    • http://yaqeen-eg.com/userfiles/file/85268186212.pdfIn PDF document text
    • http://ctkupavna.ru/upload/file/lutukudubegerapi.pdfIn PDF document text
    • http://thevelascofamily.com/clients/11614/File/goteforidanu.pdfIn PDF document text
    • http://evpltravel.com/xv_image/file/272694831.pdfIn PDF document text
    • https://momsgardenfoods.com/ckfinder/userfiles/files/zakususukiwobeka.pdfIn PDF document text
    • https://ketgate.eu/wp-content/plugins/super-forms/uploads/php/files/bb6c51f3bd296150aa980da8539f6b28/2059462297.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612e174fbe789---pafokijilumaxelubizir.pdfIn PDF document text
    • http://cipetbhopal.com/webimg/files/wexajaradefa.pdfIn PDF document text
    • https://brahmagnanam.org/fck_uploads/file/dolobitepifenewimol.pdfIn PDF document text
    • http://jiuxingchaoshi.com/uploads/file/310850474575.pdfIn PDF document text
    • http://giustizianuova.it/userfiles/file/38878332230.pdfIn PDF document text
    • https://msr-hudsonproperties.com/wp-content/plugins/super-forms/uploads/php/files/9788a1fdb76f6c367391b414d8b4c1d7/ranomuvedanijituv.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=solid+waste+technology+and+management+christensen+pdf+downloadPDF 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_off000119f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119F5 11340 bytes
SHA-256: 067bfacab63b3a65768221dfb24b6070b8a6aa590824c5f5d7b39547a4b19d63
font_01_sfnt_off00013443.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13443 16920 bytes
SHA-256: 1aa83bad7623442d399a70c908de0c7d06385925503335e6a96078b97cac5d96
font_02_sfnt_off00015fd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15FD9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1