Malicious PDF — malware analysis report

Static analysis result for SHA-256 56d83e5933b1ca9e…

MALICIOUS

PDF

98.1 KB Created: 2021-09-12 15:24:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 388935a0419c16f06349ce0c126442e4 SHA-1: b0ee599c52ed2b88987eb8af942c65235f0484ed SHA-256: 56d83e5933b1ca9e18d06906fbf883f2989212b1328842b1f7ab4293b9a46db9
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, with multiple heuristics indicating it functions as a link farm. The PDF contains numerous external URIs and links to other PDF files hosted on compromised CMS uploads and disposable hosting, suggesting a phishing or malware distribution scheme. The primary purpose appears to be directing users to malicious external content rather than containing an embedded exploit.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 https://crysiq.ru/uplcv?utm_term=sad+but+true+quotes+about+life PDF link annotation
    • https://mosaicopeoplecorporation.com/ckfinder/userfiles/files/tetizasetiwofikibutorodek.pdfIn PDF document text
    • http://blueleaves.ru/userfiles/file/64842855643.pdfIn PDF document text
    • http://gesundezellen.de/neu/userfiles/file/zedadufopododames.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/949fvilajsabgdo031kdf8bpi6/xodifugusuka.pdfIn PDF document text
    • https://mygoaltv.com/ipp/images/uploads/files/96744833653.pdfIn PDF document text
    • http://occahomesearch.com/userfiles/files/wuxoxadabili.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613900532833c---99508778696.pdfIn PDF document text
    • http://lnianemarzenie.pl/userfiles/file/fibavamajavaburadoguvan.pdfIn PDF document text
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c70f12232f---mitixevuwaj.pdfIn PDF document text
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/9ed50ca6a383934731ea1d0fe7e35516/7952302940.pdfIn PDF document text
    • http://cn-polylysine.com/d/files/tugebemojonesoxeletotigal.pdfIn PDF document text
    • http://studiomalpocher.it/userfiles/files/78487376050.pdfIn PDF document text
    • https://postelezmasivu-ostrava.cz/ckfinder/userfiles/files/mediga.pdfIn PDF document text
    • http://z-sinpro.com/upload/files/70693694777.pdfIn PDF document text
    • http://cathyknightwaite.com/ckfinder/userfiles/files/46536778286.pdfIn PDF document text
    • http://konferencii.org/web/uploads/assets/file/bunodutezi.pdfIn PDF document text
    • http://oldadmin.k12cart.com/media/files/lujosuponis.pdfIn PDF document text
    • http://gptools.net/userfiles/file/58652476447.pdfIn PDF document text
    • https://condicionamentofisico.com/arquivos/file/zitunazakixuzib.pdfIn PDF document text
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/161398d5a0ec77---52457428915.pdfIn PDF document text
    • http://hfnhsw.com/upload/files/83245596417.pdfIn PDF document text
    • http://brkvinc.com/userfiles/file/19853092773.pdfIn 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://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_off00011a90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A90 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000132a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x132A7 10704 bytes
SHA-256: a4f6140fe791d4844d8efd4642dc76050f90d44eb6e6e3740c21e7c6fbf7b912
font_02_sfnt_off00014b10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14B10 18432 bytes
SHA-256: 21280d3ced7ab92cd7addf518c5596eb1e0292f8ba1e5b19d6d36b2f34db2b64