Malicious PDF — malware analysis report

Static analysis result for SHA-256 6cbdc4e4677920b5…

MALICIOUS

PDF

77.0 KB Created: 2021-09-11 11:13:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: f3fe8e8e24171365d6fd241198aa7875 SHA-1: 697ab6092c0d0ac44004785e654f370db166b312 SHA-256: 6cbdc4e4677920b59c4314c3c40196928c75d5bbbea19bbf19d7e2bd575649ad
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 embedded URLs, many of which point to compromised WordPress upload directories. The ML classifier strongly indicates maliciousness, and the structure suggests a link farm designed to redirect users to potentially harmful content. No scripts were extracted, but the overall pattern points to a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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=how+to+change+applock+password PDF link annotation
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ba58e21d88---94758425817.pdfIn PDF document text
    • http://artediapharma.com/upload/files/venonakixela.pdfIn PDF document text
    • http://rockhouseschool.com/rockhouse/uploads/files/46876008161.pdfIn PDF document text
    • https://combrooncom.com/contents/files/xobupibo.pdfIn PDF document text
    • http://asude.istanbul/ck_images/files/9996152924.pdfIn PDF document text
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613002f6e298a---88278048915.pdfIn PDF document text
    • http://dekoblickfang.de/userfiles/file/koxenuvefufivebuba.pdfIn PDF document text
    • http://www.loicadesacavem.pt/wp-content/plugins/formcraft/file-upload/server/content/files/16130b1d064776---31762688005.pdfIn PDF document text
    • https://ratodua.com/contents/files/jusizoz.pdfIn PDF document text
    • http://hstechno.com/userData/ebizro_board/file/tofomurikogowav.pdfIn PDF document text
    • http://www.weilandensemble.nl/ckfinder/userfiles/files/ruwafufalede.pdfIn PDF document text
    • http://mywayrtk.info/userfiles/file/sasolatufalikibijolu.pdfIn PDF document text
    • https://firsatpin.com/calisma2/files/uploads/27883494747.pdfIn PDF document text
    • https://bfull.ru/uploads/files/bebuva.pdfIn PDF document text
    • https://www.aukuras.org/ckfinder/userfiles/files/vugafukid.pdfIn PDF document text
    • http://www.majbrno.cz/uploads/files/pufozizizu.pdfIn PDF document text
    • https://traffictkt.com/viking1/uploads/files/jokirodaxiburimowemeni.pdfIn PDF document text
    • http://www.somdattabasu.com/fckimages/file/nuxanarejanebudanoxeke.pdfIn PDF document text
    • https://soenen-pneus.com/upload/file/tadajekipugevo.pdfIn PDF document text
    • http://polskienarty.pl/data/aktualnosci_imgs/file/60585588972.pdfIn PDF document text
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/16132e4f0af28a---womirosoluzemapazuxow.pdfIn PDF document text
    • https://dadrarad.ro/userfiles/file/66006537973.pdfIn PDF document text
    • http://elandtour.com/FileData/ckfinder/files/20210901_4A8BE2845100C716.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_off0000c7ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7AE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dfc5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFC5 10872 bytes
SHA-256: 91b81451a7cab33ade2886d8e1435fdb84666a0cc158b801fa207077e2436583
font_02_sfnt_off0000f8b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8B3 17708 bytes
SHA-256: 2fdeef56064cc09615d0c0f644e60f7b9916c459bce4f5c23e121d86556c14eb