Malicious PDF — malware analysis report

Static analysis result for SHA-256 f38cb0ea8785a87f…

MALICIOUS

PDF

79.5 KB Created: 2021-09-07 19:07:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: e1edfecd5acfe83fb4fc5b89e8133eac SHA-1: da37966b072d647ff0cd0d5acfcb5c933f137155 SHA-256: f38cb0ea8785a87ff20e0a837fb8626fbe8cbf99342859d2c9b361ced4c82708
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to what appear to be compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards a phishing or malware distribution scheme leveraging external URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://chixue.com/uploadfile/file/20210716174118.pdf In PDF document text
    • http://vaness-sens.fr/ckfinder/userfiles/files/74811348305.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611cde135a285---dowedowerojeji.pdfIn PDF document text
    • http://santeh.md/img/files/kugivuzefid.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e217474f01e---1643899819.pdfIn PDF document text
    • http://presssimayeshahr.ir/pic/file/bixivikedex.pdfIn PDF document text
    • https://arerp.kr/data/file///peburolox.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ca011546a7a---77968263994.pdfIn PDF document text
    • https://drticket.ir/basefile/drtiketcom/files/bumajajiwexuv.pdfIn PDF document text
    • http://caratow.nl/userfiles/file/wegojozutozoliwalab.pdfIn PDF document text
    • http://nuyewpilot.academy/wp-content/plugins/super-forms/uploads/php/files/ccdc7bce57edc401216dc7a645ae3c20/14643983989.pdfIn PDF document text
    • http://munsusa.org/userfiles/file/20210626202312.pdfIn PDF document text
    • https://vallejardin.com/wp-content/plugins/super-forms/uploads/php/files/abe003b9220dc2bec5b660fa397200c5/93179456784.pdfIn PDF document text
    • http://geose.ru/userfiles/file/76652492640.pdfIn PDF document text
    • http://emiem.pl/public/upload/ckfinder/userfiles/files/7820531671.pdfIn PDF document text
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/1608dcda072183---rewinomekenozodazeva.pdfIn PDF document text
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f082deece8---dafafodelemexitazilasi.pdfIn PDF document text
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073467640c65---98162779604.pdfIn PDF document text
    • http://spiregene.com/image/files/20210812_134856.pdfIn PDF document text
    • http://www.alwaysflorida.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f6dc8b297e---kulilak.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a2c3294c70d---87821611636.pdfIn PDF document text
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/160f05b50d4d91---26297103531.pdfIn PDF document text
    • http://chiengthai.com/file_media/file_image/file/82639646516.pdfIn PDF document text
    • http://endustriyelkiralama.com/wp-content/plugins/super-forms/uploads/php/files/fij9a3mjg468l8lg4rvullivt6/88023911283.pdfIn PDF document text
    • http://www.hon-ro.hu/userfiles/files/ritiniletimatovobopigox.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=de+sonhar+tambem+se+vive+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_off0000cee3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEE3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e6f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6F5 19616 bytes
SHA-256: 0dda523dab5b8a52e95e53acb201f21b62204743d131520fd7adc052a6791e9c
font_02_sfnt_off00011724.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11724 10924 bytes
SHA-256: 6d1bc82d3c4005289052366078b879f52b1191364364a158f77ec63fe7098c0d