Malicious PDF — malware analysis report

Static analysis result for SHA-256 b25f0f6527a9e5c0…

MALICIOUS

PDF

81.9 KB Created: 2021-08-26 11:22:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 6de00725d56d727e02342b40bcf8d3e0 SHA-1: 1e93fb205032924f76e7440fa4cc1b4779a289e6 SHA-256: b25f0f6527a9e5c0e65577d47ca37151aada554fd2e68445b5c365dd52718ae8
96 Risk Score

Malware Insights

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

The PDF file contains a large number of external URIs, many of which point to compromised WordPress sites or disposable hosting domains. This suggests the document is designed as a link farm, likely for SEO poisoning or to distribute further malicious content. The ML classifier strongly indicated maliciousness, supporting this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://crewmak.ru/uplcv?utm_term=baby+chart+percentile PDF link annotation
    • https://airshow-bg.com/file/xefigiwajinupub.pdfIn PDF document text
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608f670163f8f---dukejolesaxabuwoxoxeboj.pdfIn PDF document text
    • https://chaletsuenodesol.de/files/piborikazawefabepaxinarix.pdfIn PDF document text
    • https://kopari.hu/files/file/tiwupasolekifokipo.pdfIn PDF document text
    • https://thefertilizergranulators.com/d/files/96362714935.pdfIn PDF document text
    • https://wlao.on.ca/wp-content/plugins/super-forms/uploads/php/files/fa71ac2204c0d3ae7fa2e5f8e970d358/varunu.pdfIn PDF document text
    • https://promocionesnma.com/wp-content/plugins/super-forms/uploads/php/files/d4fb0417efeb3d053abe9a89963ae0b0/96389332908.pdfIn PDF document text
    • http://quiltingacademy.com/fckeditor/userfiles/file/samolo.pdfIn PDF document text
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/ee35a88be1c0fad7dcf4b77d1671d6b3/24430208463.pdfIn PDF document text
    • http://shriadinathbank.com/uploads/wojuvubipovodezinanuduvuw.pdfIn PDF document text
    • http://tv-kitchen.ru/files/files/52982350376.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609693824193c---jojageduvexudur.pdfIn PDF document text
    • http://rooptex.com/uploads/womuwe.pdfIn PDF document text
    • http://baraanduliaptti.org/userfiles/file/92082829549.pdfIn PDF document text
    • https://www.micd.edu.np/ckfinder/userfiles/files/44227807371.pdfIn PDF document text
    • http://wsystem.sk/userfiles/files/11263488257.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608baf3682647---gelegokegigovusenirar.pdfIn PDF document text
    • http://dancephoto.ru/userfiles/files/komuzeruvatazafo.pdfIn PDF document text
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bec1f4ccc07---78027474687.pdfIn PDF document text
    • http://dolphinkorea.com/files/files/xemonisiretugeteme.pdfIn PDF document text
    • http://cancercareresearch.com/userfiles/file/ludaxalunumubawefega.pdfIn PDF document text
    • http://clinicaveterinariagoitese.it/userfiles/files/74995592169.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_off0000e0c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0C0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f8d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8D7 10488 bytes
SHA-256: 4a8d83329ad4e6eb680d788464398195b553d4d911016e365e3a2b617b12ecd7
font_02_sfnt_off00011069.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11069 16112 bytes
SHA-256: 48651a78ebe573593a852be9c606e47fec336a5dfbef72ca1228205bc6a2c714