Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3c06cf10e2215d0…

MALICIOUS

PDF

70.3 KB Created: 2021-09-13 13:38:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: f6539165f2165fcaeea844df31c2af14 SHA-1: 05fff78a3b2e07a053e74c62e215f25d48659c0a SHA-256: a3c06cf10e2215d0dbff8a0ee0c4381e182fa52ba69a730d15bb4a850adb67d1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links, many pointing to compromised WordPress sites, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://suemsas.com/wp-content/plugins/super-forms/uploads/php/files/rbn61rufpi2df7u1bmqjopffs5/43646754409.pdf In PDF document text
    • http://medrea.ru/upload/files/80974809604.pdfIn PDF document text
    • https://kltccompany.com/ckfinder/userfiles/files/61250076536.pdfIn PDF document text
    • https://plewmal-d.com/Uploads/files/2462816725.pdfIn PDF document text
    • http://cross-winds.in/upload/contents/images/images/34681158487.pdfIn PDF document text
    • https://crcnueva.naturasoftware.com/uploads/images/files/78295787247.pdfIn PDF document text
    • https://hsiaoying.com/userfiles/file/vorimugolo.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/22391c66689ea92e4a689135d06416bb/70633362497.pdfIn PDF document text
    • https://duhocblueocean.vn/ckfinder/userfiles/files/lixawez.pdfIn PDF document text
    • http://goodtraefarm.com/ckupload/files/28515830461.pdfIn PDF document text
    • https://ht-cooling-j3t.com/contents/files/37874774601.pdfIn PDF document text
    • http://logtech.cz/foto/Image/file/95462574004.pdfIn PDF document text
    • http://ansing.nl/userfiles/file/42028662502.pdfIn PDF document text
    • http://lamay.de/userfiles/file/dipani.pdfIn PDF document text
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/qegaq17veedoenm4pg72na8g4b/zejulabin.pdfIn PDF document text
    • https://underworldgear.com/admin/images/fckImg/file/zuvunodaziwewaxo.pdfIn PDF document text
    • https://pellevah.com/upload/files/ziribaduxajogubazagisoj.pdfIn PDF document text
    • http://seosanhrd.com/userfiles/file/makotuwarapesubi.pdfIn PDF document text
    • https://martabaktelor.com/contents/files/51963735996.pdfIn PDF document text
    • http://hvezda-pardubice.cz/files/file/59070478946.pdfIn PDF document text
    • https://datatalk.ilvzhou.com/upload/files/2021/09/202109081515283108.pdfIn PDF document text
    • http://webinaris.biz/ckfinder/userfiles/publics/files/todebavedisodozowevesoto.pdfIn PDF document text
    • https://pieseautocomenzi.ro/userfiles/file/23434763404.pdfIn PDF document text
    • https://hetodon.com/fckeditorfiles/file/kixuvipapedozuwi.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16136ee4114a52---vokotuzewakanezuvumosum.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=mortal+kombat+9+ppsspp+android+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_off0000b31f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB31F 10900 bytes
SHA-256: ebcbcca1349ed478ce60aafa64e38f15a0b194f0cb93a0ce08f20695867896e8
font_01_sfnt_off0000cc2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC2D 14936 bytes
SHA-256: 259b8f37cca0f901b01023aa0ef9d0ada6c24f7c4105ffce96951a018ddc9178
font_02_sfnt_off0000f183.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF183 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1