Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a566136f8756b51…

MALICIOUS

PDF

83.5 KB Created: 2021-09-14 04:52:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 39db41599a41ed06110ba52a62d71dfa SHA-1: 3a1d06f5a2c25ddf9b16ca0a2fa9e815ef775391 SHA-256: 5a566136f8756b51ca93dce03f61833d61af4bb2977ecd1b15af6feb68ef45c5
156 Risk Score

Malware Insights

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

The sample was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, with numerous URLs pointing to various websites, some of which are hosted on compromised WordPress installations. The presence of multiple external URIs and link farm heuristics suggests an attempt to redirect users to malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://istvietnam.com/rich_editor/file/48973642528.pdf In PDF document text
    • http://abwlargo.com/uploads/files/liluda.pdfIn PDF document text
    • http://mdtrend.hu/files/file/vumuwud.pdfIn PDF document text
    • https://rosanaalvarracin.com/userfiles/file/wazetobovaluzalidodipen.pdfIn PDF document text
    • https://www.terraton.com.my/ckfinder/userfiles/files/42399927128.pdfIn PDF document text
    • https://leo.tw/upload/ckeditor/files/27451280664.pdfIn PDF document text
    • https://dedywiredja.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131dc1c93f52---60878263929.pdfIn PDF document text
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16133cf9217a0b---raviwarifeweg.pdfIn PDF document text
    • http://munnarinfo.in/userfiles/file/13434611286.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/rk1n0da2nmn6rq5q79lar6ej24/tupekeduxumivo.pdfIn PDF document text
    • http://nena-artspace.com/ckfinder/userfiles/files/vodibatenogavax.pdfIn PDF document text
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/b652f7046e1db295c180e47399f7ce22/fepewodimasit.pdfIn PDF document text
    • http://ladyvenus.it/userfiles/files/78463934383.pdfIn PDF document text
    • http://oprandi.it/userfiles/files/gegetomigupugeve.pdfIn PDF document text
    • http://jongauger.com/ckfinder/userfiles/files/jaluziwiwovexet.pdfIn PDF document text
    • http://zechnerbau.at/images/content/files/82614156161.pdfIn PDF document text
    • https://nikoljski.com/ckfinder/userfiles/files/22440572881.pdfIn PDF document text
    • https://fiscalonline.ro/app/webroot/files/userfiles/files/2501012792.pdfIn PDF document text
    • http://www.magicapro.it/wp-content/plugins/formcraft/file-upload/server/content/files/16138d05435166---mogegifi.pdfIn PDF document text
    • http://vimbark.sk/editor_uploads/files/54471979618.pdfIn PDF document text
    • http://baigeleather.com/userfiles/file/77567623996.pdfIn PDF document text
    • http://93564497.com/userfiles/80133880379.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ea3883f5ef---pumebuwevipapivi.pdfIn PDF document text
    • http://runnersavezzano.it/public/userfiles/file/digedabaxasavusiji.pdfIn PDF document text
    • https://aspaeng.com/files/image/files/8675775955.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=sword+art+online+akihikoPDF 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_off0000dcfb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCFB 19848 bytes
SHA-256: 22e1d321544a14f41f8aefa56e111b0027767dfe090341b5e893d9259bb88fbc
font_01_sfnt_off000110d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110D2 10428 bytes
SHA-256: 1fe8d62b56c9ff4e2f881813e1b78b14e0599782969c358749bca52c9ec7663f
font_02_sfnt_off00012869.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12869 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1