Malicious PDF — malware analysis report

Static analysis result for SHA-256 55966840d5ada3fb…

MALICIOUS

PDF

92.9 KB Created: 2021-08-13 01:42:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 76b4b07256d473b51190281505cf7516 SHA-1: 61f7385d3825d3ad95a4071a251eaf2c9da6d7fb SHA-256: 55966840d5ada3fb2714fef7d3f5a8e8d51b30a9205040c16c9366237d522207
164 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to other PDF files hosted on compromised or disposable domains, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://skybuildinfraprojects.com/uploads/gufidodozit.pdf In PDF document text
    • https://ecomassage.pt/wp-content/plugins/super-forms/uploads/php/files/28hcbp3n7c6m901tj0msjta2iq/29517998592.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bcd09b97b13---mumutudurixuvisofuzo.pdfIn PDF document text
    • http://debeight.net/UserFiles/File/99622137898.pdfIn PDF document text
    • https://laps.pl/userfiles/file/sovofavekujilupipi.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608550717d220---biremuzakuduxex.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/c041e2086982b0bea1938c67a6da8e7d/45404765771.pdfIn PDF document text
    • https://villamishkan.com/310renonew/front/images/files/44757413276.pdfIn PDF document text
    • http://sun-green.nl/ckfinder/userfiles/files/30808237109.pdfIn PDF document text
    • http://dataction.org/demo/dataction/media/2537563586.pdfIn PDF document text
    • https://ocvirapuato.com.mx/wp-content/plugins/super-forms/uploads/php/files/dd46cbd83fa4a3f2c73c026c83feb531/50107743701.pdfIn PDF document text
    • https://eccdc.org/application/webroot/userfiles/file/23177156574.pdfIn PDF document text
    • https://cashmeredreams.com/wp-content/plugins/super-forms/uploads/php/files/230cb43b7b6e8c8b0ba7c400a572d47c/87556806455.pdfIn PDF document text
    • https://doucetplasticsurgery.com/ckfinder/userfiles/files/samuv.pdfIn PDF document text
    • http://www.adatechotomasyon.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608491a2ae3f7---67511515752.pdfIn PDF document text
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ef6619905a---fususojititixemudisivuna.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608056d6aed77---jorekanilojatasapatewite.pdfIn PDF document text
    • http://studiodabo.eu/userfiles/files/28735067796.pdfIn PDF document text
    • http://maekuangudomthara.com/ckfinder/userfiles/files/xanadixofovawi.pdfIn PDF document text
    • http://www.webtony.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16084246340738---rirenoberoruv.pdfIn PDF document text
    • https://vleek.com/uploads/files/84740666453.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a2137c4f981---zizedumomax.pdfIn PDF document text
    • http://witnesstherealist.com/wp-content/plugins/super-forms/uploads/php/files/90de15f696994ae4fe0fbaeca0292447/67050932172.pdfIn PDF document text
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/984887db8f3e01fe21f467f57f287724/87595260578.pdfIn PDF document text
    • http://sahamit.net/userfiles/file/47806575981.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=does+jason+actually+die+in+the+burning+mazePDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001058b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1058B 11364 bytes
SHA-256: 84e4f89744c3fcd0907a32959e3e6545ce7aca322d56dab6a1babc038a09dc32
font_01_sfnt_off00011ff0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FF0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013802.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13802 17004 bytes
SHA-256: 5f54e1fe98053b267ab105a2b99ce0410ff529c5232bc21bac8933c25978d501