Malicious PDF — malware analysis report

Static analysis result for SHA-256 a861c49e8adb6ca0…

MALICIOUS

PDF

91.9 KB Created: 2021-09-23 00:55:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: eb8e1c50a84f5fcdbae67e8db7f3de1e SHA-1: 64013884e878d66ee4636713d6b660b7961360d1 SHA-256: a861c49e8adb6ca03438d2a6efa64485643e25ca37bfd54ebf839640ff89c997
96 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to domains identified as disposable hosting or compromised CMS uploads. The ML classifier strongly indicated maliciousness, and the heuristic firings suggest this PDF is part of a link farm designed to manipulate search engine results or distribute malicious payloads. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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 https://archism.ru/uplcv?utm_term=advantages+and+disadvantages+of+single+use+plastic PDF link annotation
    • http://gro-felix.si/uploads/73445560269.pdfIn PDF document text
    • https://tmtteks.com/files/94267662998.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/c6f752fc4a09feafa3b7869664998365/gixikiligidazotirosa.pdfIn PDF document text
    • http://qianlong99.org/ckfinder/userfiles/files/modorimari.pdfIn PDF document text
    • http://appextskihjthj.handysociality.com/upload/files/soxibolu.pdfIn PDF document text
    • http://cmsrecuperocrediti.it/images/file/padomisijomijujatasodasej.pdfIn PDF document text
    • http://safarang.com/basefile/files/wefefajazigo.pdfIn PDF document text
    • https://888nv.ru/userfiles/file/mewadunofirizijotakazesom.pdfIn PDF document text
    • http://egitara.com/upfiles/files/pepusina.pdfIn PDF document text
    • http://ttmplus.com/userfiles/files/rijuridagikidutekefe.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/9vjv7ks5bvhrogrd6020ertiap/57430940356.pdfIn PDF document text
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/6q2v20r668mn76nbel9caskllf/93083873541.pdfIn PDF document text
    • http://bfttacg.marketsearching.com/upload/files/guwitasadonumofi.pdfIn PDF document text
    • https://artgallery.devctn.com/ckfinder/userfiles/files/ritumopagejetozewomezedob.pdfIn PDF document text
    • http://polishedskincare.com/minaret/uploads/file/44811324024.pdfIn PDF document text
    • https://www.dentaltaxpros.com/wp-content/plugins/super-forms/uploads/php/files/498ebfc690e9f636a055426373a62281/32868524968.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/8833e55c31657c58297c359e19b4be4f/98123521655.pdfIn PDF document text
    • http://commissioncollectionlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/jafigalamab.pdfIn PDF document text
    • http://husplaza.hu/editor_up/91606460583.pdfIn PDF document text
    • http://xy-interior.com/uploads/files/202109082248254246.pdfIn PDF document text
    • https://leise.ru/admin/ckfinder/userfiles/files/65106740601.pdfIn PDF document text
    • http://dorp.pl/userfiles/files/gugerimatamup.pdfIn PDF document text
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/lj043lnh9o7cn64v1jfhghacb3/4099759494.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_off00010261.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10261 10844 bytes
SHA-256: 084d55231633436aaa0b64107b7ca0f47184ebb9fdffae2915208c874c677511
font_01_sfnt_off00011b67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B67 17652 bytes
SHA-256: 62d529815c9735907f4047d7c0bda09e7b940333242daa5d242d1db0cab5cddf
font_02_sfnt_off00014959.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14959 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1