Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc78105f4a6c89b8…

MALICIOUS

PDF

88.2 KB Created: 2021-09-01 10:25:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f4912a271d699261b818a6036169d4c3 SHA-1: cdcdeb4c293eee690cd539a920812a66c0ff7f14 SHA-256: dc78105f4a6c89b8d986b7a8ae5dbe55b7f8de712c8d9afc42ca5802a200aff1
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample contains embedded JavaScript and numerous external URIs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to obscure the final malicious destination. ClamAV and ML classifiers strongly indicate malicious intent, likely for phishing or malware delivery. The embedded JavaScript is a primary mechanism for executing malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9979

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/695b8518f02730c3a9952a69842a8a2f/54212128052.pdf
    • http://szguilong.com/userfiles/files/10436497974.pdf
    • http://verduciautodemolizioni.it/userfiles/file/roseguzisi.pdf
    • https://www.traveltimevipp.com/wp-content/plugins/super-forms/uploads/php/files/4d981dcb1d5f81c18e5a4922c4b281a3/defupi.pdf
    • http://musiconthebay.org/clients/2/26/269dd5bc96e197da989a8dccc71442af/File/99718042071.pdf
    • http://www.thaiboat.net/image/upload/File/10535470434.pdf
    • http://timnhanhonline.com/upload/files/xedetexipudezatatona.pdf
    • http://austria-ex.com/images/blog//file/wobunimi.pdf
    • http://www.awakohchang.com/image/upload/File/akidoxewideban.pdf
    • http://grupomarsamo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087b641c60c1---16271857366.pdf
    • https://lecachet.fr/docs/files/92544652223.pdf
    • http://daieimotors.com/js/upload/files/femupizifunenesurerenade.pdf
    • https://seerupit.dk/assens/file/kalevubikusedenegeve.pdf
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/60e9319ac51bdfec2ca6e7dcced382fe/90962039098.pdf
    • http://cmcthailand.com/ckfinder/userfiles/files/fimigureri.pdf
    • http://plenar.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16075bdfc693e4---jaxevi.pdf
    • http://www.cpiequipos.com/assets/images/user_files/files/sikeroxonadexosoba.pdf
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607623bfb78d8---88784534592.pdf
    • https://duvanco.be/docs/files/fadave.pdf
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160aa15906921f---65100458026.pdf
    • http://chiangmai-esc.net/user_img/files/lukanopumiraj.pdf
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/cee6be4a0823f6907945e7dfb3c70725/37197182325.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=aging+breast+tissue
    • 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_off0000f736.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF736 16792 bytes
font_01_sfnt_off00010f48.bin
cb15cf1d04992da45db5809f95878959756d8f251118d15537565936be6f6af8
pdf-font-stream PDF embedded font (sfnt) at offset 0x10F48 17344 bytes
font_02_sfnt_off00013c0d.bin
bc913eee4cada2f497e22f222c73e5dd23ac5a57bf95877b6f2cefaa014da60b
pdf-font-stream PDF embedded font (sfnt) at offset 0x13C0D 10336 bytes