Malicious PDF — malware analysis report

Static analysis result for SHA-256 8fec2b10a31b2528…

MALICIOUS

PDF

68.2 KB Created: 2021-09-25 02:57:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 7470f9bbd3813a7cf5a646d735a85ff9 SHA-1: f04795d40be389be6ea668b3a82257f429f26b0d SHA-256: 8fec2b10a31b252852ad590c80b58b9dc673a2ac8aa776f9dda2b03cda3810d1
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. The presence of numerous embedded URLs pointing to various PDF files suggests a link farm or SEO manipulation tactic. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a strategy to distribute content across many domains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://spbmedax.ru/sites/default/files/uploads/96219578296.pdf In PDF document text
    • http://nenayu.com/filespath/files/20210925065132.pdfIn PDF document text
    • http://educasters.co/ckfinder/userfiles/files/gajagetuxoxaz.pdfIn PDF document text
    • https://www.kindspring.org/inc/ckfinder/userfiles/files/72344298294.pdfIn PDF document text
    • http://milkyway-vn.com/upload/files/wumidileg.pdfIn PDF document text
    • https://bodzlomu.com/userfiles/file/62182017093.pdfIn PDF document text
    • https://apexsafetyproducts.com/ckfinder/userfiles/files/wojegoxesan.pdfIn PDF document text
    • https://dnsbp.com/all4help/fckuserfiles/file/29090870304.pdfIn PDF document text
    • http://onishi-kyosendo.jp/archive/8335787853.pdfIn PDF document text
    • https://tsolisp.com/files/file/fekaromigazalis.pdfIn PDF document text
    • http://myagreement.com/UserFiles/file/82599890852.pdfIn PDF document text
    • http://mcap.cz/images/uploadedimages/file/dovenidijaparixowimira.pdfIn PDF document text
    • http://dohertylaw.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/vaxufosanefurevab.pdfIn PDF document text
    • http://lex-ter.ru/admin/ckfinder/userfiles/files/20559877495.pdfIn PDF document text
    • https://fitness-sport.it/userfiles/file/wevudabojako.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132766dcbf38---3574939883.pdfIn PDF document text
    • http://willettelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/welefisobu.pdfIn PDF document text
    • http://pcccphucvinh.com/upload/files/xenorisanemawosafe.pdfIn PDF document text
    • http://doubles301.jp/files/ckeditor/files/tefakatokup.pdfIn PDF document text
    • https://marlin-aquarium.ru/ckfinder/userfiles/files/64092236620.pdfIn PDF document text
    • http://webminmax.com/userfiles/file/pewejefonuwaxelitovipipu.pdfIn PDF document text
    • http://aumnat2car.com/ckfinder/core/connector/php/upload/files/kugefotilejededobezabimek.pdfIn PDF document text
    • https://damsindia.org/admin/uploads/file/jozukagunofiziz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=zombie+drift+mod+apk+downloadPDF 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_off0000ad9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAD9E 14892 bytes
SHA-256: ccb80aeb9d711bbf4b5fe6685c1b857ce1b7dd36be2f08b6dc4a1a2643abdea4
font_01_sfnt_off0000d2dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2DD 10772 bytes
SHA-256: 5a82ccbd9fcabc4390d4647d5e50af5a9a069bde64a6355bc79aa4e39a18be85
font_02_sfnt_off0000eb78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB78 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1