Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b8955cab21b80fe…

MALICIOUS

PDF

83.3 KB Created: 2021-09-02 10:29:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 9b93f0e90d3aed018e6c9208e6bcf565 SHA-1: b4e57c8b08ea22bc9c5d578478e4a247bdeb67d9 SHA-256: 3b8955cab21b80fec2b088f967855e001bf05985970287549cd6af636c955e39
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm. Multiple heuristics indicate the PDF contains numerous external URIs and links to potentially compromised CMS upload storage, suggesting an attempt to redirect users to malicious sites. Although no scripts were explicitly extracted, the nature of the links and the PDF structure strongly imply a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://pixomot.ru/uplcv?utm_term=yucca+plant+life+cycle PDF link annotation
    • http://nhadep30giay.com/uploads/image/files/jabalirubufejawufapa.pdfIn PDF document text
    • https://nhatngudongkinh.com/upload/ckupload/files/27163164744.pdfIn PDF document text
    • https://kapokcmassage.com/uploads/files/202108181043534053.pdfIn PDF document text
    • http://gdfsztal.com/uploadfile/files/48099733833.pdfIn PDF document text
    • https://abeess.com/userfiles/file/72601994422.pdfIn PDF document text
    • https://beysukonaklari.com/ckfinder/userfiles/files/36848565775.pdfIn PDF document text
    • http://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c96ea179dcb---tivujeriguge.pdfIn PDF document text
    • http://arcdesantmarti.com/biocop/Images/images-editor/file/57362443945.pdfIn PDF document text
    • http://scherzerpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/12421050906.pdfIn PDF document text
    • https://nanyangtextile.com/userfiles/file/jiwibu.pdfIn PDF document text
    • https://eduinfinite.com/wp-content/plugins/super-forms/uploads/php/files/44b8d900dfc574dc93541d08fcf12c97/tokijo.pdfIn PDF document text
    • https://mygo.com/ckfinder/userfiles/files/41884804261.pdfIn PDF document text
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074c476d4e92---timazarumokipitap.pdfIn PDF document text
    • http://sualaptoplayngay.com/ImagesVA/file/virevuvegusuwuxowam.pdfIn PDF document text
    • https://airshow-bg.com/file/zamivowutawevuzekagabuk.pdfIn PDF document text
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160df6bef2ce4a---mijuveberax.pdfIn PDF document text
    • http://xenangheli.vn/public/files/80982060234.pdfIn PDF document text
    • https://interesttour.com/wp-content/plugins/super-forms/uploads/php/files/011b7f8dea68f777a1b99f5fdc8a4ce3/85488866831.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609dd050acbea---26370948491.pdfIn PDF document text
    • http://fantalife.nl/userfiles/file/15265735053.pdfIn PDF document text
    • http://brooklinehs1964.com/clients/6/6a/6a3559cec3eb17f551da2d864c8c85ab/File/81790809294.pdfIn PDF document text
    • http://hyundaiokla.com/uploads/files/55805637510.pdfIn PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609845d658ca5---45136068571.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/16092b6504e1ab---pixila.pdfIn PDF document text
    • 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_off0000dfa9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFA9 10284 bytes
SHA-256: 90111e964f403a649a00d337e4e75060c08f875b7328ab520924933a2e260b66
font_01_sfnt_off0000f6ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6EE 18720 bytes
SHA-256: e52e805bdfd1a901638ca0d4e1c600b07f4c5069388ad2db67581804a3995f3d
font_02_sfnt_off00012716.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12716 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1