Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8a09b92a48f8751…

MALICIOUS

PDF

81.8 KB Created: 2021-05-07 02:36:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: a9ac25432de82771beed2103f82c4a71 SHA-1: a5304ea5c1f03b4ef479593aa189e7ae021c8698 SHA-256: f8a09b92a48f87517ec4aa47f9ad50277f98eeae805243aeda97111c4aeb81ae
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution via these links. No scripts were extracted, and the document body was heavily obfuscated, preventing a more detailed analysis of the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://www.kocay.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1607251220c0a2---nenawapekukudidiverun.pdf In PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/645af6bb228e541e9010ef61d31567ea/lulegesujobunef.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16085b1d480c54---basazobajubodowijituro.pdfIn PDF document text
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/0c9cf41425e42b5ada0dc410e9a62421/xisusurufig.pdfIn PDF document text
    • http://garderoba.sk/images/_file/nabugufamotavasomozamo.pdfIn PDF document text
    • https://shared401k.com/wp-content/plugins/super-forms/uploads/php/files/8cfaa0b956a089f9596a07ac32474f19/mijuwuwuzisudamumuzo.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/1nc63744e8nljm8lhpo3kiflq1/45219818592.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081fe5b411b4---latuvogegukoveragiz.pdfIn PDF document text
    • https://ercrs.org/wp-content/plugins/super-forms/uploads/php/files/6iq13bilbunceov0cj4i8ofrpj/5173097320.pdfIn PDF document text
    • http://workprohealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092e86fcf544---2339374318.pdfIn PDF document text
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f113ac2269---56438733611.pdfIn PDF document text
    • http://guides2alpes.fr/uploads/file/bolubuviwapefider.pdfIn PDF document text
    • http://www.pianoszimmermann.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160876f04188a0---xapubujidita.pdfIn PDF document text
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/160945aebd71ed---vojevajibewukeze.pdfIn PDF document text
    • https://www.accidentinjuryalbuquerque.com/wp-content/plugins/super-forms/uploads/php/files/kogn317mt4ceb9rvadjcsr186m/wokaporega.pdfIn PDF document text
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160781207e08a2---92028465860.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=behavioural+economics+textbook+pdfPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001014b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1014B 5776 bytes
SHA-256: ce7ee34deec88b02808d6e7af6055b6b7e62918b96f91fc1943953fa8a6a1468
font_01_sfnt_off000114ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114CE 10460 bytes
SHA-256: edaedf35d8d6c2e0f6077078bf3b1b847be405930cb6dc92b3448a99bdb935d3