Malicious PDF — malware analysis report

Static analysis result for SHA-256 fd811d9855c70aa9…

MALICIOUS

PDF

70.9 KB Created: 2021-09-27 15:43:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fe4748cf8bb2344f801f831f1086e16b SHA-1: 69a3a3a935d1be51f07be2d90554696d779adfa8 SHA-256: fd811d9855c70aa96cc59e2ad735da828ca238a69ffff265e15dff9468f8fb7f
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, and exhibits characteristics of a PDF link farm. Multiple heuristics indicate the PDF contains numerous external URIs and links to disposable or compromised hosting, suggesting an attempt to redirect users to malicious content. No scripts were extracted, but the structure and URL patterns strongly suggest a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://wastran.ru/uplcv?utm_term=d%26d+3.5+character+sheet
    • http://hugslock.com/app/webroot/img/files/gikusubusimutep.pdf
    • https://gkatsov.com/userfiles/file/vewitavesixudixeg.pdf
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/161438d8ae3904---84749498598.pdf
    • https://eventaipei.com/upload/files/77682899207.pdf
    • https://daquin-ferriere.fr/userfiles/file/84449154381.pdf
    • http://www.trisad.kz/ckfinder/userfiles/files/pokodolumagopirirununu.pdf
    • http://sbstroy53.ru/img/files/52093426217.pdf
    • http://homelife-superstars.com/image/files/tukaxiju.pdf
    • http://danangsculpture.com/uploads/image/files/rijumopodi.pdf
    • https://gbp.dropship-online.com/userfiles/files/30340687268.pdf
    • http://e-hematologica.pl/users/file/78520323426.pdf
    • http://handinks.com/ckfinder/images_store/files/pusasojujuzojemabapus.pdf
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16132cb181af79---8996871349.pdf
    • http://vo23.ru/upload/file/dixomilijisitiro.pdf
    • https://onlinendttraining.net/files/41493093174.pdf
    • https://termoformat.md/img/files/31442108297.pdf
    • http://okna-stv.ru/userfiles/files/pejezabopenalexipepibute.pdf
    • https://hahapediatric.com/uploads/files/202109022109388755.pdf
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613992dc5d7fa---6266120435.pdf
    • http://tsg-edinstvo.ru/userfiles/file/romopokopesam.pdf
    • http://dighakanchaninternational.com/FCKeditor/file/93426634868.pdf
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613f6f989e397---51800166874.pdf
    • http://letdentalab.com/img/files/tuworalab.pdf
    • http://detskypohar.cz/upload/file/76221885237.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b6e7.bin
acfd7fb77ea1a256318809d20310205799c5d85c667d98ca8225a9be13b68b93
pdf-font-stream PDF embedded font (sfnt) at offset 0xB6E7 17540 bytes
font_01_sfnt_off0000e34f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE34F 16792 bytes
font_02_sfnt_off0000fb65.bin
f695977626623e59fedb2fbedebd468d0acf89ff6f6ceafeb3cee4351ddee6c8
pdf-font-stream PDF embedded font (sfnt) at offset 0xFB65 9076 bytes