Malicious PDF — malware analysis report

Static analysis result for SHA-256 79f1b859e93b91d0…

MALICIOUS

PDF

79.5 KB Created: 2021-09-07 23:34:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a39ca0adcfa7d0b9bbe6f03b31c1554c SHA-1: 123c731276d5364dc009e80a7139660bb8796266 SHA-256: 79f1b859e93b91d07fc9fd046c4b5e2dd728df6da523f27c4c9b555af9be3902
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm with numerous URLs, many pointing to compromised CMS upload directories, suggesting an attempt to distribute malicious content or phish users. The ClamAV detection and ML classifier strongly indicate malicious intent. Although no scripts were explicitly extracted, the nature of the link farm and the compromised hosting implies a malicious workflow, likely involving redirection to phishing sites or malware downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/b12913a3961e91458dc84b617aeb40a5/74913793676.pdf
    • https://szalkasszorutacskok.hu/app/webroot/files/content/files/nikiligavizamisuwolapi.pdf
    • https://funcarele.com/ckfinder/userfiles/files/60152740790.pdf
    • http://studioguatta.it/userfiles/files/wamitonofofekorobigod.pdf
    • https://parkettworld.com/upload/files/18336078917.pdf
    • http://dataction.org/demo/dataction/media/85515653256.pdf
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/160924fdfbe1ac---85547076982.pdf
    • http://www.moteco.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160bddc1157f39---14238860873.pdf
    • https://vinisfarm.com/wp-content/plugins/super-forms/uploads/php/files/874c5be00e9f6f88c7d1ccea960b5b82/63615298880.pdf
    • http://beautybybelief.com/admin/images/file/razevogulirepot.pdf
    • https://amenajarisiconstructii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607ecd69c99e9---11815283469.pdf
    • http://www.euro-fly.eu/userfiles/files/95930685498.pdf
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/160cd97b3713b1---dezotorebetazedupebolu.pdf
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096b8a226f52---wamasi.pdf
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c8ea30cdbc0---34210533948.pdf
    • https://charqueadaboavista.com.br/wp-content/plugins/super-forms/uploads/php/files/8700d2b6824713086475ba2989691e89/pixedopudimilefusukuwu.pdf
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1612705acdc082---detapuwunatanuva.pdf
    • http://trackeg.com/en/wp-content/plugins/formcraft/file-upload/server/content/files/16076aff614104---goxojijolezowagiweb.pdf
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/404fe61a93bc6a34f77d886e129ab108/39893424675.pdf
    • https://www.mii.net/wp-content/plugins/super-forms/uploads/php/files/728b5a8115e13df53109aeffb2b5519a/lepepatonasekoluk.pdf
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16123e7dd18cb9---67115980617.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=common+and+proper+nouns+worksheets+for+kinder
    • 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_off0000d112.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD112 16792 bytes
font_01_sfnt_off0000e924.bin
299dc13a76436e74094e19fe54e1825d23e71c3d574b3477da023acd2e21b436
pdf-font-stream PDF embedded font (sfnt) at offset 0xE924 17876 bytes
font_02_sfnt_off000116dd.bin
2a86b30fedc151ce70526425b465b64fd030978c30538d16b73031f320fcec4e
pdf-font-stream PDF embedded font (sfnt) at offset 0x116DD 11024 bytes