Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9f491e64fa1ad52…

MALICIOUS

PDF

69.3 KB Created: 2021-09-17 06:09:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 31e7239524cb00767c7266b42aa1ca76 SHA-1: 32862b67a86cc601bb05befbeaefa97d42ea98a2 SHA-256: a9f491e64fa1ad52680a631a982cd126ffd54e2f6a070580c919171a837993ab
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress upload directories or disposable hosting. The ML classifier strongly indicated maliciousness, and the heuristic firings confirm the presence of a link farm designed to lead users to potentially harmful sites. No scripts were extracted, but the structure and URL distribution suggest a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://irlanc.ru/uplcv?utm_term=collective+noun+with+examples+in+sentences PDF link annotation
    • http://modra-skola.cz/userfiles/file/dabobobajodozimurudovisen.pdfIn PDF document text
    • http://e-district.org/userfiles/file/pavufiwovatobibeselekaji.pdfIn PDF document text
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/6aa6b5d4b6fd386c8aa8322930eef557/89067534899.pdfIn PDF document text
    • https://gestcargo.com/uploadfiles/file/28666714723.pdfIn PDF document text
    • http://espicycooking.com/files/file///porulimutotoxokola.pdfIn PDF document text
    • http://muaah.ca/userfiles/files/42802559167.pdfIn PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613a285c9a184---81366423998.pdfIn PDF document text
    • http://domario.ru/userfiles/file/purowu.pdfIn PDF document text
    • http://www.hz-kontejnery.cz/ckfinder/userfiles/files/vajofexiwoj.pdfIn PDF document text
    • http://uspeh-kursk.ru/ckfinder/userfiles/files/bopodokufizakiwejiregom.pdfIn PDF document text
    • https://umiyawoodworks.com/fckdb/userfiles/file/sasebonumuba.pdfIn PDF document text
    • https://adlinefor.com/home/webagen/public_html/korn/data/file/95270519352.pdfIn PDF document text
    • https://kaunas.cvzona.lt/resources/img/files/kowomobirelizugamujog.pdfIn PDF document text
    • http://3duct.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614401160ed01---62532694157.pdfIn PDF document text
    • http://lblussana.it/images/file/58685065576.pdfIn PDF document text
    • http://waypl.pl/upload/File/tudijetolitex.pdfIn PDF document text
    • https://palet-school.com/files/files/49091284754.pdfIn PDF document text
    • http://urs-certification.com/gais/image/file/99550767555.pdfIn PDF document text
    • http://mzch.pl/userfiles/file/54288551059.pdfIn PDF document text
    • https://emmaushuis.org/pages/wavisenexalazafes.pdfIn PDF document text
    • https://goldmenu.com/userfiles/file/21579688738.pdfIn PDF document text
    • https://perfecthospital.net/FCKeditor/file/34793874487.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_off0000b12a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB12A 10924 bytes
SHA-256: c4dcc217fa482e7e9d145491e5b7774250ab15f8df93ad6df6ee40fb76c04446
font_01_sfnt_off0000ca65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA65 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e277.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE277 14876 bytes
SHA-256: fbbb1ea448d463fb2c39f2c6294ee72bcc4e3cdefb04f0aeb9cebdc82eec252d