Malicious PDF — malware analysis report

Static analysis result for SHA-256 e9c9ba09f106287a…

MALICIOUS

PDF

83.8 KB Created: 2021-09-19 17:03:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: b6f007125747598cf70467a2d672b693 SHA-1: 3739be9778708a3abe1d89073e90346317356792 SHA-256: e9c9ba09f106287a768918c4e8f8d61c7b7934e5cce9ace4634829e65c0c3534
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to manipulate search engine rankings or distribute malicious content. The ML classifier strongly indicated maliciousness, and the presence of external links aligns with initial access via spearphishing. No scripts were extracted, limiting the analysis of direct execution vectors.

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 https://krisoc.ru/uplcv?utm_term=how+to+change+sharing+options+on+android PDF link annotation
    • http://thestarbusan.com/FileData/ckfinder/files/20210916_3F01D033926A567E.pdfIn PDF document text
    • https://excellencetogether.com/img/files/file/12420055007.pdfIn PDF document text
    • https://deniz-sogutma.org/img/userfiles/file/kamugurivopupurufoji.pdfIn PDF document text
    • http://www.peritaonline.es/ckfinder/userfiles/files/dobujuvupegogomiju.pdfIn PDF document text
    • https://www.karavanlakesfet.com/wp-content/plugins/super-forms/uploads/php/files/3f7c4a857194f5ec8a2301fe131c603d/91579291588.pdfIn PDF document text
    • http://canphantich.net/Images_upload/files/molizu.pdfIn PDF document text
    • http://karate-talence.com/newsite/userfiles/files/60489760374.pdfIn PDF document text
    • http://leaguengn.com/userfiles/file///56267617508.pdfIn PDF document text
    • http://nato-denkmal.de/uploads/file/19634233344.pdfIn PDF document text
    • https://sensiblemachines.com/ckfinder/core/connector/php/files/86721390764.pdfIn PDF document text
    • http://9jamail.com/FCKeditor/editor/filemanager/connectors/userfiles/file/metilomolo.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e55978fd8f---kexowimaxixilirafi.pdfIn PDF document text
    • http://www.xn----9sbkvfu2aex3d.xn--p1ai/ckfinder/userfiles/files/mimiposozuzafem.pdfIn PDF document text
    • http://tulga.ru/editor/files/49851122589.pdfIn PDF document text
    • http://aromamahabaleshwar.com/ckfinder/userfiles/files/87200046429.pdfIn PDF document text
    • https://allcondosales.rodeodrivecondosale.com/userfiles/files/kiwunadimifeviba.pdfIn PDF document text
    • http://sushistoryus.com/uploads/files/32785508447.pdfIn PDF document text
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143cd60cd249---22674715322.pdfIn PDF document text
    • http://remont-etalon.ru/upload/files/dowozozarebixixorokalub.pdfIn PDF document text
    • http://bienchidan.org/uploads/files/6537618294.pdfIn PDF document text
    • https://hoovermaids.com/wp-content/plugins/super-forms/uploads/php/files/edf6a89392d454098eca4b859a5afafb/74037063369.pdfIn PDF document text
    • https://hiperaktivite.info/userfiles/files/17899398086.pdfIn PDF document text
    • http://dinskayarealty.ru/media/file/mobijaxolagerilov.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_off0000dfe2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFE2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f7f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7F9 10824 bytes
SHA-256: 80659d183b87a3fa043f0801b0ee32f95dbe746bd984d0b8ffb98008a22a6dbd
font_02_sfnt_off000110b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110B4 18928 bytes
SHA-256: a75b46ad420df77005f066082ac33e4ab77e93109413581da22568b995986701