Malicious PDF — malware analysis report

Static analysis result for SHA-256 b71a4f8e4a645324…

MALICIOUS

PDF

96.9 KB Created: 2021-07-01 01:05:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: c43dc1ad41348d067defb297fc415580 SHA-1: ee799b559441ec93f7432b12994dcd753c805e9e SHA-256: b71a4f8e4a645324229fbae7014a7dd3136e076f2d3403e877782d792d7590d6
156 Risk Score

Malware Insights

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

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, pointing to numerous compromised CMS upload locations and disposable hosting sites. The PDF's structure and embedded URLs suggest it is designed to lure users to external, potentially malicious content, likely as part of a phishing or credential harvesting campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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 http://s8radziejowice-paszkow.pl/userfiles/file/74218514426.pdf In PDF document text
    • http://cleannshieldflorida.com/wp-content/plugins/super-forms/uploads/php/files/9db46de21bb684f2e618075e01909d50/71670396089.pdfIn PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/16094cd9d7dd45---wofoworexemixuful.pdfIn PDF document text
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609516d039bc5---lebedosakomozodilosoram.pdfIn PDF document text
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/afb30b7e1a09f677f1fad5fa41b421c5/6330940696.pdfIn PDF document text
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16084c972db929---paguvamodolubele.pdfIn PDF document text
    • https://hram-uspeniya.ru/ckfinder/userfiles/files/73418523181.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/85ivbsi00utcl28dk82lff784v/suvot.pdfIn PDF document text
    • http://xn--9p4b29dncp2cc6y.net/upload/fckeditor/file/boxapumobupek.pdfIn PDF document text
    • https://wilsonbarrera.com/inicio/wp-content/plugins/formcraft/file-upload/server/content/files/1608d609f767d3---56044732185.pdfIn PDF document text
    • http://www.sarajevo-inn-grunewald.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c44e78287ce---28606209983.pdfIn PDF document text
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/0fbd02dac7bffc907bee9fde9ce76827/27031456557.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16076f4fea03d0---26388611819.pdfIn PDF document text
    • https://evg-prague.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1606f1e7b37941---rizepegotam.pdfIn PDF document text
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/m2q7bgf215t2q7gkdonkbkcspb/funevesojose.pdfIn PDF document text
    • https://hansenlight.com/UploadFile/files/zurapefogipazat.pdfIn PDF document text
    • https://markzone.az/wp-content/plugins/super-forms/uploads/php/files/jq7m27np7l84pdis15er1t34o6/2512550432.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dee905aee0---81119678424.pdfIn PDF document text
    • https://zazilha.com.mx/wp-content/plugins/super-forms/uploads/php/files/ae42b0525d7de673be9ff4d8e2d8a462/31979346121.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160bf972786f5d---97948160064.pdfIn PDF document text
    • https://ecobox.eng.br/wp-content/plugins/super-forms/uploads/php/files/febc0oq0e3dk19n4va8d7jt7ln/dituditusudefiwumuwita.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=powerful+short+wordsPDF 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_off0001176b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1176B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012f7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F7D 18196 bytes
SHA-256: 5a025e62f06960051a18702d2b12a90298aba91bdaabe8619ee8d54016112760
font_02_sfnt_off00015de9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15DE9 10280 bytes
SHA-256: 71fbd7a53dee8884b85da890c0e6845df946b20fd7c6ed49840adcb35dd42168

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