Malicious PDF — malware analysis report

Static analysis result for SHA-256 c37cc4e44da539e6…

MALICIOUS

PDF

83.8 KB Created: 2021-06-27 20:27:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7c7705f19cc12e7f04e9ce195f2ef525 SHA-1: b0c536218aaa27bc37f500c14555222ec54b6b67 SHA-256: c37cc4e44da539e655c1592bb59b2cceb1eef89b8a93734f5c1dd15b01416f54
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable domains, indicating a link farm designed to manipulate search engine results or distribute malicious content. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious link farm attack pattern. No scripts were extracted, limiting the analysis to the URL structure and heuristic findings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • 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://marketypik.pl/zdjecia/fck/file/94932953493.pdf
    • https://functionalmovement.gr/wp-content/plugins/super-forms/uploads/php/files/cc3b48330ae8dd2196cfd93d356a8e4f/kijimezo.pdf
    • https://roofmed.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160be2e3d3d986---budoz.pdf
    • https://papiratisk.cz/soubory/nanoloxozitatozuvo.pdf
    • http://fixmyhelicopter.com/project-new/christianbook/upload_images/file/xerevitusugojazo.pdf
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/160811abe7c949---zogiwugabevabameredefuna.pdf
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/d9qjt1fn5jbiuavtkcfkk8ub5j/96253406623.pdf
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b2d4f3e9d5c---jezuregaja.pdf
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16072f82b942f8---10621833275.pdf
    • http://antifftech.com/uploadfile/file///2021050113011230.pdf
    • https://sindonis.com/userfiles/file/femijesoxotipevel.pdf
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f95b67d682---84856162062.pdf
    • https://monarchwinemerchants.com/wp-content/plugins/super-forms/uploads/php/files/c1355ae5b6b045b9e7e09e55c677a450/62508367460.pdf
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/fa9ddbdeb4ea26ce7528db5eae2c43f3/9390705289.pdf
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a0eeba9c248---rujutebudamimuvef.pdf
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/d79d3d84ec2bc4f78a127ba9e14d57ba/zemuratopadogegeg.pdf
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/c0a5c297122d7ebae991b15876b7968e/raliteru.pdf
    • http://biomassasia.net/data_ed/userfiles/file/nepejipiwavenix.pdf
    • https://mrmobilewebsite.agency/wp-content/plugins/super-forms/uploads/php/files/7668a8ded5c4e8f97a45d8471750eb45/liruwatusatalux.pdf
    • http://holzbau-napetschnig.at/rosasakusakiwijaxiv.pdf
    • http://steakclubhn.com/campannas/file/fekogazisu.pdf
    • https://costumeworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/160837ac09bb4b---wemelalasoj.pdf
    • http://baraanduliaptti.org/userfiles/file/29631943566.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=normal+bilirubin+levels+in+2+month+old
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e5b0.bin
b7c60bb4635f98b8482a637808f8da7f440c215b00265a483fe9e522660e3d12
pdf-font-stream PDF embedded font (sfnt) at offset 0xE5B0 16460 bytes
font_01_sfnt_off00011093.bin
1f042e937c30f67d7218d35048657e549064c7c347c79c1e81f602e36c01e70a
pdf-font-stream PDF embedded font (sfnt) at offset 0x11093 10916 bytes
font_02_sfnt_off000129b8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x129B8 16792 bytes