Malicious PDF — malware analysis report

Static analysis result for SHA-256 81cfe6490fbd69be…

MALICIOUS

PDF

88.2 KB Created: 2021-09-06 01:02:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: df009f051754adb851da5af0494e3f96 SHA-1: 39c085a09825568c88bf9d6fb3f66a410aeb8e0a SHA-256: 81cfe6490fbd69be2b6a411e821f37434dd607d70d1ecfe1636133993b6f960f
156 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains a link farm pointing to multiple distinct hosts, many of which appear to be compromised WordPress sites or disposable hosting, suggesting a phishing or malware distribution campaign. The presence of numerous external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

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://walkandsmile.com/userfiles/file/susejavogefedidafax.pdf In PDF document text
    • http://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0077dc9310---58062751175.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608fa9c22a689---delidifukiputepedemi.pdfIn PDF document text
    • http://fleshlight-tw.com/userfiles/file/49592351086.pdfIn PDF document text
    • http://heryeryesil.com/resimlerfiles/zimezumizujuteviwapijofe.pdfIn PDF document text
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160b5479ab2694---dinekobe.pdfIn PDF document text
    • http://debandhelder.nl/ckfinder/userfiles/files/20325043255.pdfIn PDF document text
    • https://habibitours.com/ckfinder/userfiles/files/73501816712.pdfIn PDF document text
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1891645e2d---54555914544.pdfIn PDF document text
    • https://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/ctja9e48843t6q3f6hm7d0orj2/16669294081.pdfIn PDF document text
    • http://tatvideo.ru/ckfinder/userfiles/files/63446620295.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16080df81e25d1---xojabalabajokiwus.pdfIn PDF document text
    • http://sprinter-lab.ru/content/File/21533775950.pdfIn PDF document text
    • http://www.logomarcanet.com/userfiles/file/videvetuzereraro.pdfIn PDF document text
    • http://oletrans.sk/editor_uploads/files/nevelowolofejo.pdfIn PDF document text
    • http://cosmic-kino.ru/sadm_files/kixusebegaxabavutorudo.pdfIn PDF document text
    • http://vestmorecapital.com/images/epost/84989996462.pdfIn PDF document text
    • http://www.bridalchapel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607056bb732c9---wevafonixavoxinaj.pdfIn PDF document text
    • http://cmuniontravel.com/userfiles/files/87919864793.pdfIn PDF document text
    • http://marcus-1.com/FileData/ckfinder/files/20210529_B98CBC88A7683298.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=reflow+pdf+onlinePDF 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_off0000f443.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF443 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010c55.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C55 18604 bytes
SHA-256: 5251a17d01ccf56a7a3cd5a265ce09da91c2bc2a433326a541d33b0f447b4509
font_02_sfnt_off00013cef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13CEF 10096 bytes
SHA-256: a97b67bf2acc2ae261dd6990ad5372b96fa9002b6225f9cadf94be7766996676