Malicious PDF — malware analysis report

Static analysis result for SHA-256 fc727d6a8e00c423…

MALICIOUS

PDF

81.4 KB Created: 2021-09-01 16:04:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 220c710a1b4b9b937cd43faceebfb88e SHA-1: b9e16a2e816bc2bd6a3561db8ebe9fce59289542 SHA-256: fc727d6a8e00c423af4d6a70c09a8c82f8cab50a21d38082e2d00107816ac9f1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was detected as malicious by ClamAV and an ML classifier. It contains a link farm with numerous URLs, many pointing to compromised CMS upload directories, suggesting an attempt to lure users to malicious content. The document body is heavily obfuscated and unreadable, but the presence of multiple external URIs and the 'link farm' heuristic indicate a phishing or redirection attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6707

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://studioriggio.it/userfiles/files/8769243611.pdf In PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ca0f0792d91---37785242505.pdfIn PDF document text
    • http://lyzjkgm.com/d/files/kizuwenagafomuru.pdfIn PDF document text
    • https://abrasco.org.br/ckfinder/userfiles/files/vosotonasivofa.pdfIn PDF document text
    • https://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/0bf3a7e6a16550a769753689f4ab25e6/29671952282.pdfIn PDF document text
    • https://howardsteeves.com/wp-content/plugins/super-forms/uploads/php/files/b514904877aa25576f96aab5b166b87a/69501334394.pdfIn PDF document text
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f1ac6ef74f---79019004119.pdfIn PDF document text
    • http://agataklimowska.pl/userfiles/file/dazuxu.pdfIn PDF document text
    • http://thriftstorewebsites.net/flash/thriftstorewebsites.net/file/depaze.pdfIn PDF document text
    • https://habibitours.net/ckfinder/userfiles/files/widulitafimogaju.pdfIn PDF document text
    • https://dalilak1.com/userfiles/file/votevuximoko.pdfIn PDF document text
    • https://hotelritariccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607cd897a7d5d---28246905525.pdfIn PDF document text
    • https://art-gallery.mn/uploads/files/31786314988.pdfIn PDF document text
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16086cb7adb85a---16183716442.pdfIn PDF document text
    • https://polnische-zaune.de/userfiles/file/74225506083.pdfIn PDF document text
    • http://associacaoguainumbi.org.br/wp/wp-content/plugins/formcraft/file-upload/server/content/files/160886db878328---25845315581.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607bd9375814b---xapasazonabusuzuxol.pdfIn PDF document text
    • https://calldidocta.com/wp-content/plugins/super-forms/uploads/php/files/f2b6c6181762c157e24e38841a385f4f/46344755340.pdfIn PDF document text
    • http://cerescommoditiesltd.com/Images_upload/files/47238272499.pdfIn PDF document text
    • https://nacionalequipamentos.com/ckeditor/uploads/files/tofenowasi.pdfIn PDF document text
    • https://amatnieks.lv/pictures/image/73004345573.pdfIn PDF document text
    • https://www.sahabatkeluargahomecare.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e5c191e498---33372471438.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=watch+knocked+up+online+123PDF link annotation
    • 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_off0000e00b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE00B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f81d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF81D 18136 bytes
SHA-256: e503bf9e5a991897d3b1cdd83e98f798f77dbab3973c53932cd493bdafb85faf
font_02_sfnt_off0001270e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1270E 10872 bytes
SHA-256: 4a274dd3e3b03b8b7c0d100868ba9bfdf82628192c236677035554ad30c91f2d