Malicious PDF — malware analysis report

Static analysis result for SHA-256 81ee85281aee82be…

MALICIOUS

PDF

81.2 KB Created: 2021-07-01 18:13:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 404958ff811fd41c6084262e52ed7a81 SHA-1: 37b8c490c22419fedf337ce2d34e087709264626 SHA-256: 81ee85281aee82be50e7b2445252c3883df1ed8478992bc71a9d039952aa4d84
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress upload directories. These links likely serve as a distribution point for phishing or malware, aiming to exploit user interaction with the provided links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c304f86251b---27173606709.pdf In PDF document text
    • https://metricgroup.it/uploads/file/43406157371.pdfIn PDF document text
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f466914699---20619080702.pdfIn PDF document text
    • http://lnianemarzenie.pl/userfiles/file/piwekivizebozugabe.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160ba6e9e41347---gubedawotobodogelada.pdfIn PDF document text
    • https://mimpishio2bet.com/contents//files/7209910204.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/160a01c057a54f---fofafu.pdfIn PDF document text
    • https://expeditions-travel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb8a18963d---35633287610.pdfIn PDF document text
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/28dc6a3a6c4ff8d1d8636c91e0cc9883/fedexirif.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16084b0cb45714---7092857208.pdfIn PDF document text
    • http://andreaslasnik.com/data/files/nabisogojomuwixozuzutolo.pdfIn PDF document text
    • https://bestofbucerias.com/upload/file/13411416926.pdfIn PDF document text
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5228ce8971---buxasimomukitikofa.pdfIn PDF document text
    • http://poltinik.ru/userfiles/file/30225241581.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=meaning+of+blatePDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c1bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1BF 18408 bytes
SHA-256: 2cc7d870f3c768e5cb79acb0db418d39113821c3f6c367872736761cbc783ab4
font_01_sfnt_off0000f1db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1DB 16476 bytes
SHA-256: 9d09c70c619ba324ee192f3639d45cc4a3ad6fd7cc7100666640d48859dc318b
font_02_sfnt_off000108a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108A4 10252 bytes
SHA-256: c8633a38fe80a07f58924b99febe21fb5ee6b2da8a33b7d13f5ec9bb56340484
font_03_sfnt_off00011fca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FCA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1