Malicious PDF — malware analysis report

Static analysis result for SHA-256 8bde4f6ef7badad3…

MALICIOUS

PDF

74.8 KB Created: 2021-09-05 14:29:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: cb7223181188c226446c8f8541239a57 SHA-1: af0b4adf893198a7ec290b8453afcb55e4fc34c5 SHA-256: 8bde4f6ef7badad32f059529adf6bc8c7d9e27cf4c853c733115d8c10b6fb88a
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious. It contains numerous links, many pointing to compromised WordPress upload directories, suggesting it functions as a link farm. The presence of these links and the nature of the heuristics indicate an attempt to direct users to potentially harmful external content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ede23fb491d---jufivokonun.pdf In PDF document text
    • http://amirafouad.com/uploaded_files/file/fanizega.pdfIn PDF document text
    • http://wypelnienia.kratex.pl/wp-content/plugins/super-forms/uploads/php/files/3c70c1b27e7fa4e830d1d2046928c8b2/musonumovanerezotenovo.pdfIn PDF document text
    • https://x-software.cz/data/file/gifumedevedibomojojejupe.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607718cbc9269---6451358380.pdfIn PDF document text
    • http://tehla.eu/userfiles/file/94936110754.pdfIn PDF document text
    • http://rungruangsteel.com/public/upload/userfiles/files/zivived.pdfIn PDF document text
    • http://frangarcia.eu/upload/file/ledowutagem.pdfIn PDF document text
    • http://beetsom.com/PROGRAM_FCKeditor_UserFiles/file/177251005460a4695d59f79.pdfIn PDF document text
    • https://darkoyunpin.com/calisma2/files/uploads/guradopogesujav.pdfIn PDF document text
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16080e9eb885c0---kefuxatapamomitabofagu.pdfIn PDF document text
    • https://www.brightfieldbusinesshub.co.uk/wp-content/plugins/super-forms/uploads/php/files/r8tbo2chi8bavkpbovm00gatmg/xuturezotikutetusimaba.pdfIn PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbcca0649be---90767329797.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7b14e325a8---ruzatugodo.pdfIn PDF document text
    • https://tckontrola.hr/files/wufopugezerawiziwa.pdfIn PDF document text
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/1610068c46b971---54498855883.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e94b99e9c9b---54263957494.pdfIn PDF document text
    • http://sotel-perm.ru/site/file/15180561255.pdfIn PDF document text
    • http://www.hydro-tg.pro/upload/file/xatudokataniruxexud.pdfIn PDF document text
    • https://kham.vn/userfiles/file/noperevinomifikisejow.pdfIn PDF document text
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609dfa587f65a---damij.pdfIn PDF document text
    • https://www.ediliziaindustriale.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073a2701c7e9---sipodetokukapixet.pdfIn PDF document text
    • http://gavinlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/vumagunogaposojeg.pdfIn PDF document text
    • http://polaryachts.com/res/wysiwyg/file/36516922442.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=intermediate+vocabulary+longman+pdfPDF 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_off0000c010.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC010 11164 bytes
SHA-256: 755475ac200a7d626a418a6e9b9577554829c2b92b08f23819f6d84b4c4db2b0
font_01_sfnt_off0000d9bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9BB 16956 bytes
SHA-256: a3adbec29a75531f7348c8ebaf399ada1618e94e39ebfebb7243de00458ffb9a
font_02_sfnt_off000105c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105C2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1