Malicious PDF — malware analysis report

Static analysis result for SHA-256 ab3f425a2ea324a5…

MALICIOUS

PDF

73.0 KB Created: 2021-09-30 22:51:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: b0e43873afba687013a652e03db6ce21 SHA-1: 16356f9778e87304c6d7021f656e2b990a7a6a25 SHA-256: ab3f425a2ea324a56c46be44fd96e726a93bf6f78526d5006631613e263c2439
96 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by an ML classifier and contains numerous embedded URLs. Several heuristics indicate it functions as a link farm, with some links pointing to compromised WordPress upload storage and others on disposable hosting. The document body is heavily obfuscated and unreadable, suggesting it's not intended for human consumption but rather to host links.

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 http://vigen12.com/userfiles/file/11803986826.pdf In PDF document text
    • https://cruiseship.cruises/wp-content/plugins/super-forms/uploads/php/files/ak72osc5prj1tinonkqnp8k9kf/bemexu.pdfIn PDF document text
    • http://www.pattyn360.com/upload/forum/files/46108303572.pdfIn PDF document text
    • https://duel.pl/userfiles/file/1246056396.pdfIn PDF document text
    • http://yurisolomko.com/userfiles/file/rawix.pdfIn PDF document text
    • https://tecnibat.net/uploads/archivos/48034320168.pdfIn PDF document text
    • http://rickgrisolia.com/userfiles/files/45944118582.pdfIn PDF document text
    • http://tunglamgarden.com/images/fck/file/fagovuduzetig.pdfIn PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/1613e90d6eb382---fetenepidupufitubevipupum.pdfIn PDF document text
    • https://tongdaidoanhnghiep.com/app/webroot/upload/files/vuxapodabotamo.pdfIn PDF document text
    • http://vibestedu.com/_UploadFile/Images/file/dipujozivegovoditivux.pdfIn PDF document text
    • https://watosaphotography.com/app/webroot/userfiles/files/20210913_224953.pdfIn PDF document text
    • https://investkwik.com/userfiles/file/11371540356.pdfIn PDF document text
    • https://ercrs.org/wp-content/plugins/super-forms/uploads/php/files/5smsh7u5jk78c8cai881npcfr2/zuwuborutokivixizele.pdfIn PDF document text
    • http://stavebnevyrobky.sk/www/upload/files/67265519604.pdfIn PDF document text
    • https://havadisname.com/upload/ckfinder/files/47983480765.pdfIn PDF document text
    • https://aimtronu.org/userfiles/file/71132861437.pdfIn PDF document text
    • http://xn--zb0by3yusal20ak5lcidnwigi.com/ckfinder/userfiles/files/1632713388.pdfIn PDF document text
    • http://nbc.com.vn/ckfinder/userfiles/files/63247921982.pdfIn PDF document text
    • http://nyitotthaz.hu/userfiles/files/jifuzipade.pdfIn PDF document text
    • https://mattress-leader.com/media/33942207001.pdfIn PDF document text
    • https://mintedimages.com/ckfinder/userfiles/files/74448009270.pdfIn PDF document text
    • http://1qjd.com/upload/files/2021-09-15-20-03-17-4cvU8XPD.pdfIn PDF document text
    • http://sarkanyhajo.hu/files/file/miviten.pdfIn PDF document text
    • http://efuegypt.org/userfiles/file/48411636251.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=pnc+virtual+wallet+android+appPDF 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_off0000b773.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB773 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cf85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF85 17416 bytes
SHA-256: 07b212cacdc2ef87f125719a5a53eb7ab826aa9cda1df6cd3012e93cea1d457a
font_02_sfnt_off0000fc77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC77 10592 bytes
SHA-256: c838d16604bc4e862be87c348f2e2579c182417c43b7234b87214585d59bcc1f