Malicious PDF — malware analysis report

Static analysis result for SHA-256 1651508501cb3eae…

MALICIOUS

PDF

81.6 KB Created: 2021-06-23 04:05:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 0a66e92a29fd68f8f18c7acfb6f6a242 SHA-1: 2b36bcac6de38fb905fbbc21178f2eb9a89a482b SHA-256: 1651508501cb3eae2e1d079d59f03bd44cafd5ae9c59c20be5da93f0a62a3e99
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs that point to compromised WordPress sites and disposable domains, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://catamma.ru/uplcv?utm_term=viewpager2+with+tablayout PDF link annotation
    • https://majubesar.org/contents//files/76177829834.pdfIn PDF document text
    • http://jucal.es/images/file/40775487503.pdfIn PDF document text
    • http://www.gcsystem.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1606d9bd838103---92614936705.pdfIn PDF document text
    • http://www.marcado.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608ac914415df---lunenibufexurikirufesev.pdfIn PDF document text
    • http://nw-line.ru/generic/uploaded/xuwipazoxodubodoz.pdfIn PDF document text
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/16072f3e2e1527---duxebaseponofowuje.pdfIn PDF document text
    • http://linkingpeople.info/userfiles/file/zekoparalexofonexabises.pdfIn PDF document text
    • http://amandatravel.com/userfiles/file/33510846956.pdfIn PDF document text
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160857e27333e8---kidozadubezozepobepirix.pdfIn PDF document text
    • https://discoverapartmentsforrent.com/wp-content/plugins/super-forms/uploads/php/files/fdfa942f2255da3a6302ddc804b02e30/fudumafegopefagi.pdfIn PDF document text
    • http://www.gametimecatering.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a842b52ec4c---fikogeluvoxosaxemej.pdfIn PDF document text
    • https://llsindia.in/FCKeditor/file/guwasopevanususuw.pdfIn PDF document text
    • https://bandotrading.com/uploads/file/runuv.pdfIn PDF document text
    • https://bestmiamiturf.com/wp-content/plugins/super-forms/uploads/php/files/74d30845e71bb05fc6a78aa2cbd076d9/borege.pdfIn PDF document text
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c861a23ba7---13344367072.pdfIn PDF document text
    • http://svenstavik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160adeb6c5a993---11701617533.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c624.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC624 19768 bytes
SHA-256: 186244f86cc30763ea7a8373106418c9094bf8db1b48ad4ff47fc39a7e5179a5
font_01_sfnt_off0001000a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1000A 5336 bytes
SHA-256: 4ba7a51264a5fb6aa2bb6088185d0f32b9600adf1f52ef486dfeb3e6d8fa088e
font_02_sfnt_off00011247.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11247 11396 bytes
SHA-256: 3691a83281b66f848a30ea825540c25921bc275993c0ef8f80879fabfdfbd9ef