Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f9b4d1ec1edfd31…

MALICIOUS

PDF

78.7 KB Created: 2021-06-14 19:57:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 6b5b967fac32685e95baf8aff11e735c SHA-1: ec904f0308fd813f007080c25d1a28a671cff9a3 SHA-256: 3f9b4d1ec1edfd31e5e39ce661f96ea71ceaa7f92db52371610eb4ce188db212
156 Risk Score

Malware Insights

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

This PDF was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous links pointing to compromised WordPress sites and other disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and unreadable, preventing a more detailed analysis of its specific lure.

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://cructi.ru/uplcv?utm_term=the+purloined+letter+pdf PDF link annotation
    • http://anatolianlgs.com/userfiles/file/74079577921.pdfIn PDF document text
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609179ee1b6cf---52285259938.pdfIn PDF document text
    • https://ketgate.eu/wp-content/plugins/super-forms/uploads/php/files/02caf44e4c8077ce514f323837432f0d/66017064040.pdfIn PDF document text
    • http://www.doctor-carpet.com/wp-content/plugins/super-forms/uploads/php/files/2ussv1qj2828slibdj0ptn2tu7/dudibixizevofev.pdfIn PDF document text
    • https://championsforchildren.org/wp-content/plugins/super-forms/uploads/php/files/56b4f34e8cc677aec04f93e5426cf288/xabusinokorefozadusazuj.pdfIn PDF document text
    • https://nezrenpin.com/calisma2/files/uploads/84497637136.pdfIn PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/160c3d206acc78---bovigam.pdfIn PDF document text
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608ac764beb23---kopusogopobobebipaza.pdfIn PDF document text
    • https://agrimal.pl/userfiles/file/valimufa.pdfIn PDF document text
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160adf229d5d38---78741402372.pdfIn PDF document text
    • https://activepymes.com/pub/file/kupepurojorogejuj.pdfIn PDF document text
    • http://sushiloverca.com/uploads/files/5646329151.pdfIn PDF document text
    • https://freedomtampons.com/wp-content/plugins/super-forms/uploads/php/files/9a01b1bd9f5db5eacec86837fdf63ff1/juxolokizirebow.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/tmd3r1ddrvbsuq7l1urknlrvk4/68089394632.pdfIn PDF document text
    • http://alimentosldm.com/userfiles/file/3776925035.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f80c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF80C 4692 bytes
SHA-256: 879b0d3a53f7fe192b5a38a4edda7dd3088db09fa2c8ce7c63e1dc6af1c73add
font_01_sfnt_off000107f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107F8 11596 bytes
SHA-256: dc252c06f9ef03d34bc723c1ca2f1c4f033a909d75f36b09769e69affa8fca72

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