Malicious PDF — malware analysis report

Static analysis result for SHA-256 81c1d421080250ab…

MALICIOUS

PDF

77.4 KB Created: 2021-08-30 00:46:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 30d7c10058475e4089a73dfa4b396e14 SHA-1: 997cfa9c75d149c8d71811dde84c9e0577ac4d96 SHA-256: 81c1d421080250ab875dab7e607d92a14e560bfa91014bfb4d2d4b14dda7534c
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for exploiting PDF vulnerabilities or redirecting users. Multiple heuristics indicate the PDF acts as a link farm, pointing to compromised WordPress sites and disposable hosting, suggesting an intent to host malicious content or phish users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 7

  • 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.
  • 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 http://48bulls.com/js/upload/files/87262484541.pdf
    • http://sharise.net/Uploadfiles/files/96825953555.pdf
    • http://aloeverajuice.cz/files/file/xivuzekulagizibijag.pdf
    • https://vegas-shop.net/uploads/files/zetilim.pdf
    • http://fipjp.com/userfiles/file/80088646439.pdf
    • https://www.crossfitparamaribo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b25e87bce6---58233939711.pdf
    • http://silarperu.com/UserFiles/file/bezonosavizivunujisin.pdf
    • http://www.publicitymailing.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160b3b737b5bb6---mulanaxamutazuta.pdf
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609e90e218480---busipidijagovo.pdf
    • http://cdseoulps.com/uploadfile/fckeditor/file/lisopafese.pdf
    • https://www.kadeavenue.com/wp-content/plugins/super-forms/uploads/php/files/50313b4740469a3ae62329bc52acf05c/vokek.pdf
    • https://service-panev.com/userfiles/22710394037.pdf
    • http://euro520.net/userfiles/file/16278164551411520113.pdf
    • https://kenkochaya.com/user_data/ckfinder/files/gegonuwixuxoxapowobo.pdf
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/a1eckfmsbf7kpopf6gcckjeslt/memeguwitazed.pdf
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160e2b5c0d8552---zurufurasalojeditesuk.pdf
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607fef14abb98---patamobodanapozapojixupo.pdf
    • http://lasfyy.com/uploadfile/file/20210616233112783.pdf
    • https://ovalpolycoats.com/media/26591310320.pdf
    • https://www.mtiwelding.co.uk/admin/ckfinder/userfiles/files/venonojajadosimuxuwokin.pdf
    • https://expresstestingatl.com/wp-content/plugins/super-forms/uploads/php/files/684341dc1c69350403e1d16d00d8a719/754732020.pdf
    • https://ceilford.org/wp-content/plugins/super-forms/uploads/php/files/376f0020713f428e013f475efd163ef3/21273945751.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=bollywood+hd+mp4+movies+download
    • 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_off0000c998.bin
c39bc31444970543023eb9a024fbfe9b2ae7648cd64cd58a3e58711935ff2c12
pdf-font-stream PDF embedded font (sfnt) at offset 0xC998 17276 bytes
font_01_sfnt_off0000f67b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF67B 16792 bytes
font_02_sfnt_off00010e92.bin
26e6b46987db7021d8b1beb3a37c18ebaf6e2db4c2561c0eb3c8f5c4ad7cb6ef
pdf-font-stream PDF embedded font (sfnt) at offset 0x10E92 10856 bytes