Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1b16e5043fd1d52…

MALICIOUS

PDF

88.5 KB Created: 2021-06-27 04:07:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f1857bd46a487192c7c91ee26855e063 SHA-1: e88c406b75727df7a32518694c053a66896b58c9 SHA-256: b1b16e5043fd1d5202954a3f838adc1112c34d60b3f877240682741946b612a1
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a significant number of external URIs, many of which point to compromised WordPress installations. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery through these links. The embedded JavaScript could be used to further obfuscate the malicious redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://www.assignproject.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f4f57d74e8---sonamoburamunazu.pdf
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609c6c1465895---41508083146.pdf
    • http://burningspearmarketplace.com/js/ckfinder/userfiles/files/meradusen.pdf
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/160cc32d4574bf---58649029782.pdf
    • https://www.hinogas.com/wp-content/plugins/super-forms/uploads/php/files/k80mudn9gjccif8s3sle564j70/benonomapi.pdf
    • https://101doctor.com/uploads/ckfiles/files/60bf8aeb9ed71.pdf
    • http://ladyvenus.it/userfiles/files/78657223477.pdf
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/2f7fd90cceddda7e0658170cc65739d5/lowagesurivedevu.pdf
    • http://phantasos.org/userfiles/file/28953933461.pdf
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/b49f284d2201f549997e3d2a9f40efd0/jonabonepovoto.pdf
    • http://murielbellhomes.com/userfiles/files/91464138492.pdf
    • https://semineebrasov.ro/printuri-fi/files/70581307923.pdf
    • http://retco.ge/ckfinder/userfiles/files/matodewimowitesekezediles.pdf
    • https://lightsourceindiana.com/wp-content/plugins/super-forms/uploads/php/files/b7e3270d74041021aad5724e29ba82ad/1689132108.pdf
    • https://avenue102.com/uploads/file/zevezi.pdf
    • https://butchercurnow.com/img/shop//contents/xosigobifazikobukapofese.pdf
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/160ca13b8e52e7---kulepuvi.pdf
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/16077aa03ba290---70489678616.pdf
    • http://allamericannursing.com/userfiles/file/16962964202.pdf
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/8037ec49b30c45016a2f177030ba5e55/24533894739.pdf
    • http://sowitech.vn/upload/files/zowisamewimof.pdf
    • http://www.look4job.gr/images/_user_na/file/bejimogawijona.pdf
    • http://diamondsnspurs.com/clients/12200/File/meturinukikukixinizuga.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=i+have+a+knot+in+my+calf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f636.bin
b60ba770f1cc089d98a6e44e0e1e5bf87de9b4c9ef5b802d67994c55b803b01f
pdf-font-stream PDF embedded font (sfnt) at offset 0xF636 17344 bytes
font_01_sfnt_off0001231a.bin
5bf3b4cb62f77564c02ef07e15924f04d95dde4f7bea0c8e4619af0420898841
pdf-font-stream PDF embedded font (sfnt) at offset 0x1231A 10556 bytes
font_02_sfnt_off00013b08.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13B08 16792 bytes