Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8b40fbecdeb9a84…

MALICIOUS

PDF

76.6 KB Created: 2021-09-13 15:47:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 0661bfe9787ccc4c26d7cf4a7363934f SHA-1: 5a5b91e2d205a4fd762b50acb9b1d463d8e41b4d SHA-256: b8b40fbecdeb9a84fbc3e795dae1221acbdbac06aad455a0b4e49f80d4d89ab9
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URLs, with one heuristic specifically identifying it as a link farm on disposable hosting, suggesting a phishing or redirection scheme. Although no scripts were explicitly extracted, the PDF structure and embedded URLs point towards an attack pattern involving the exploitation of PDF vulnerabilities or social engineering to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://celebicatering.com/upload/ckfinder/files/bubetizadato.pdf In PDF document text
    • http://sreema.org/FCKeditor/file/xumijuzeselolisoxamalob.pdfIn PDF document text
    • http://podiummoda.ru/userfiles/file/541778860.pdfIn PDF document text
    • http://briquettemachinery.com/d/files/67907612525.pdfIn PDF document text
    • http://maurovalleferroarchitetto.eu/userfiles/files/20091029396.pdfIn PDF document text
    • http://newgoodluckcrane.com/admin/uploadfiles/file/rijotu.pdfIn PDF document text
    • http://pharmabiosolutions.com/filespath/files/20210912093621.pdfIn PDF document text
    • http://namlinhchivietnam.net/userfiles/image/file/21125206951.pdfIn PDF document text
    • https://manhremhoangvan.com/wp-content/uploads/files/xasopujaduvakajewo.pdfIn PDF document text
    • http://www.onlinenieuwsbriefversturen.nl/gebruikers/afbeeldingen/kagebuvekopezajox.pdfIn PDF document text
    • http://bobiniauto.com/userfiles/file/30276652427.pdfIn PDF document text
    • http://ventensis.lt/public/ckfinder/userfiles/files/24381462408.pdfIn PDF document text
    • https://lightupalife.org.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161387d242d1fb---vinelivix.pdfIn PDF document text
    • http://witnesstherealist.com/wp-content/plugins/super-forms/uploads/php/files/561dbe65ddaf1a656b2c19a743470295/pidebolarotupixaz.pdfIn PDF document text
    • http://woodlandhills.ilovepokebar.com/uploads/files/tofigerukiwevasabome.pdfIn PDF document text
    • https://suthuytinh.com/app/webroot/uploads/files/tulotawuwe.pdfIn PDF document text
    • http://xenangheli.vn/public/files/wumafadiri.pdfIn PDF document text
    • http://mediacast.vn/ckeditor/upload/files/jemokabegavonivumabom.pdfIn PDF document text
    • https://tomorrowhubs.com/upload/users/files/12366917637.pdfIn PDF document text
    • http://ominocoibaffi.it/userfiles/files/77514689312.pdfIn PDF document text
    • http://globalcenterhotels.com/bot/ckfinder/uf/files/59803278324.pdfIn PDF document text
    • http://cartopack.com/Images/file/40238953005.pdfIn PDF document text
    • https://vanchuyenduongsat.vn/upload/files/tefigulewik.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=download+meme+generator+apkPDF 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_off0000c6aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6AA 17868 bytes
SHA-256: c2276627d3f7e49f7e203fac114b346b03e12d62971692993a391a3787d23ebf
font_01_sfnt_off0000f469.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF469 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010c80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C80 10656 bytes
SHA-256: 963be0b072c0c56438ed4f0e7ba347bdc11633dac12708b6fc2fbae2871b545f