Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ed8ccd14a14ee5f…

MALICIOUS

PDF

80.8 KB Created: 2021-09-07 00:02:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 55d22aa8951f8370a37fe42abe74f7db SHA-1: 87f7d8e8e3aa0167224716df325cc04381cf4b06 SHA-256: 8ed8ccd14a14ee5f46882be2407842e719ed6eba12960ac4d90c4f41abd13325
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to external PDF files hosted on various websites, many of which appear to be compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of a link farm on disposable hosting further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://skrabl.pl/www/rpbd/fck/file/lakareb.pdf In PDF document text
    • http://cuspsurgeons.com/userfiles/file/kitatukoborugoginulene.pdfIn PDF document text
    • https://eol.org.pe/ckfinder/userfiles/files/xuxupopudavoxoteg.pdfIn PDF document text
    • http://sciencevier.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b050a3456a1---mepokunomebosubevilapi.pdfIn PDF document text
    • https://interesttour.com/wp-content/plugins/super-forms/uploads/php/files/98c6bf515f1b7a2825bb0425e572ca92/nizibagetup.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076378ea14b8---wuloxewiwok.pdfIn PDF document text
    • http://lactopad.com/uploads/files/8846089541.pdfIn PDF document text
    • http://ediljolli.com/userfiles/files/82892753995.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160760b4846d3b---10808637729.pdfIn PDF document text
    • http://forter.vn/hinhanh/file/fuvuzefuladamiwu.pdfIn PDF document text
    • https://hkbca.org/UploadFiles/file/20210903043804170.pdfIn PDF document text
    • https://www.idahomedia.com/wp-content/plugins/super-forms/uploads/php/files/759509707ba893b2ede532ac87a652d5/93720603320.pdfIn PDF document text
    • http://stellar-toys.com/ckfinder/userfiles/files/5264749378.pdfIn PDF document text
    • http://animalscipublisher.com/files/upfiles/file/wisireseful.pdfIn PDF document text
    • https://evenimentecastel.ro/wp-content/plugins/super-forms/uploads/php/files/b29fliulhe9sbqi9o1jghvecgd/potowoxavivalonazizin.pdfIn PDF document text
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c7b5689dfa6---65570785701.pdfIn PDF document text
    • http://poiskvod.ru/images/file/51861783859.pdfIn PDF document text
    • http://pomocnaukowa.net/Upload/file/3041982818.pdfIn PDF document text
    • https://hotel-la-licorne.fr/userfiles/file/vokinupogamejorisojob.pdfIn PDF document text
    • http://www.fashiongale.ro/userfiles/files/89258098098.pdfIn PDF document text
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096f333d874f---91313813357.pdfIn PDF document text
    • https://alshaabcoop.com/userfiles/file/pujof.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=cesar+aira+la+costurera+y+el+viento+pdfPDF link annotation
    • 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_off0000d388.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD388 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eb9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB9A 18848 bytes
SHA-256: 7753f54b93b213ebc8d6eb0d6a4d63927cbadbf24b3b504e896ebfb95b31d035
font_02_sfnt_off00011b4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B4E 10924 bytes
SHA-256: dddd410c3e64fb2136b7fa9919d842c083b88f0bbbc68149329693a00c61a312