Malicious PDF — malware analysis report

Static analysis result for SHA-256 da5f861872d1637c…

MALICIOUS

PDF

71.9 KB Created: 2021-09-05 13:47:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 66678b2f02e410c29900d74f17c5e8b8 SHA-1: 03a56fc101f36f48dda87919b9ad221a2462755f SHA-256: da5f861872d1637c51bd309ffde3b8140af671f94b9960bff18531a891f357ea
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised or disposable hosting, indicating a link farm designed to direct users to external sites. Heuristic firings like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly support this assessment. The ML classifier and ClamAV detection further confirm the malicious nature of the file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • 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.
  • 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://iccarrentals.com/files/file/36921356739.pdf In PDF document text
    • http://noahsmarinesurveyors.ca/userfiles/file/dalodotuv.pdfIn PDF document text
    • https://www.asoriofrio.org/ckfinder/userfiles/files/boduvix.pdfIn PDF document text
    • http://sistersaviopublicschool.com/userfiles/file/wavulurapevewa.pdfIn PDF document text
    • https://foundryindia.org/userfiles/file/lajokapupepivaxeg.pdfIn PDF document text
    • http://fuzoku-kyujin.jp/ckfinder/userfiles/files/fularopakerodovofifuxise.pdfIn PDF document text
    • http://ergo-logo-bamberg.de/userfiles/file/28849835965.pdfIn PDF document text
    • http://cyklo-sport-servis.cz/UserFiles/File/7120496223.pdfIn PDF document text
    • https://corpusbg.com/files/fck/file/sivedilajotofoxa.pdfIn PDF document text
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161290459207da---manufofemi.pdfIn PDF document text
    • http://www.hgbehringer.de/img/files/files/wufewetupidemiga.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612a40d6a2af2---94894201274.pdfIn PDF document text
    • http://rowadhr.com/app/webroot/upload/files/62933329035.pdfIn PDF document text
    • http://designbeginnings.com/upload/file/xupipe.pdfIn PDF document text
    • https://granitabrasive.hu/editor_up/jevexibavuxexaf.pdfIn PDF document text
    • http://vonschickenconcord.com/uploads/files/64734882143.pdfIn PDF document text
    • https://www.ventisilva.com.br/ckfinder/userfiles/files/12886165259.pdfIn PDF document text
    • http://www.pattyn360.com/upload/forum/files/21970858635.pdfIn PDF document text
    • http://schoonhovensvrouwenkoor.nl/ckfinder/userfiles/files/80320559224.pdfIn PDF document text
    • http://markasib.ru/ckfinder/userfiles/files/wotejop.pdfIn PDF document text
    • http://www.benyowsky.com/resources/files/gebuxurazolamasitopoxije.pdfIn PDF document text
    • http://av-jet.ru/userfiles/file/54627277176.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c50c324b99---84183515772.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=manual+de+hemostasia+y+trombosis+grupo+clahtPDF 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_off0000b4a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4A8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ccbf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCBF 11308 bytes
SHA-256: 58a3fd441ee18b912beb1ef3824a12a88d1558f5b87869dabcacbf40380eea7c
font_02_sfnt_off0000e6b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6B1 16728 bytes
SHA-256: 4bf537ad2d6d186c65462ab580a23ed5b5d65663c0db4c9877ed135d4a1a5d45