Malicious PDF — malware analysis report

Static analysis result for SHA-256 dcd31a8d1527775c…

MALICIOUS

PDF

85.5 KB Created: 2021-06-26 18:25:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8562692b11ed3cf9791fb27d0cb1c736 SHA-1: 3712619b39c0cc22b299a3de39c9617fa18b37c3 SHA-256: dcd31a8d1527775ccf7f956cf0683293b48ef4f1908f306b5b67307812b4affd
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to obscure the true destination. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution. The presence of external URIs and link farm heuristics points towards an attempt to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/158976659fafe58d6d603bb87710c92e/buzefawedubenukerimesigo.pdf
    • http://thongthien.vn/upload/files/jijametegexorutavemekole.pdf
    • https://office-agglo-larochelle.fr/userfiles/file/fekibeserorexoxujupibo.pdf
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/90a32a44783cd555fa3001649152850f/87658716787.pdf
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160732d4485bc0---sejiwupepomiz.pdf
    • https://envomask.com/wp-content/plugins/super-forms/uploads/php/files/0b118c734ea288982efb7e442411b44c/44942894296.pdf
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/18b3af98b1da764e406a3ea7ffc85b82/83624235574.pdf
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0ee4f57d1d---najewosobogabubefefuwiga.pdf
    • https://flyingfish-stay.com/userfiles/file/3291161274.pdf
    • http://architects-desk.com/uploadsfile/fozijodudokemotafibekit.pdf
    • http://asahiru-ban.com/files/files/98489504001.pdf
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/c4f81b519d6117e831d6a91ebf6b753d/detimilurag.pdf
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/1031ca45205b6670a3f1ce76efd44aa1/durowanutisazamenidomeva.pdf
    • https://zlato-eu.cz/upload/files/mogovok.pdf
    • https://olgapopovaphoto.com/wp-content/plugins/super-forms/uploads/php/files/0f4522614abfd4f1cdf3bd1fbe53d27f/47920488077.pdf
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/1607cb2f09551c---25198145494.pdf
    • https://anzmrrn.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608900f84b26b---nesokowulepafi.pdf
    • https://robinio.de/wp-content/plugins/super-forms/uploads/php/files/mduuhcqfdsci1ljkksp16fpflt/16485239124.pdf
    • http://starrwindow.com/clients/863399/File/luxuvikufofu.pdf
    • https://accuratesearch.com/userfiles/file/32944572519.pdf
    • http://in-dapt.com/wp-content/plugins/formcraft/file-upload/server/content/files/160955d754664e---zaloki.pdf
    • http://www.adarshvidhyasankul.org/userfilesfile/66389114893.pdf
    • https://www.davidcosz.de/wp-content/plugins/super-forms/uploads/php/files/npv43f0lu12k33i695v8t7mumo/dovijotu.pdf
    • https://www.m2asolutions.com/wp-content/plugins/super-forms/uploads/php/files/e53175ce1beac29fac8a8d4d4209cc54/66292421499.pdf
    • http://akinmedikal.com/uploads/file/16682239818.pdf
    • http://alphasigmaoverseas.com/userfiles/file/78581158797.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=character+foils+in+romeo+and+juliet
    • 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_off0000ecae.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xECAE 16792 bytes
font_01_sfnt_off000104c5.bin
ab350f780e723ae168e381ca5fe9d54a60ca680d764bd9b785220578752aa916
pdf-font-stream PDF embedded font (sfnt) at offset 0x104C5 11000 bytes
font_02_sfnt_off00011e1d.bin
a26f7e485c6f12501177aeea3fc957bbcc3526845cffc88a7575eba84076b8c8
pdf-font-stream PDF embedded font (sfnt) at offset 0x11E1D 16628 bytes