Malicious PDF — malware analysis report

Static analysis result for SHA-256 16d8fbb4f3fd96f3…

MALICIOUS

PDF

85.6 KB Created: 2021-08-04 22:56:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 9a8ff5125489dd259caecfe23a7fd891 SHA-1: 49bceec3510c821c97fa47ad5b13cffe22a32fd0 SHA-256: 16d8fbb4f3fd96f373710f2eb21d247ba99db2ca61320aae87f4d4029b0ddc9c
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of embedded URLs, many of which point to compromised CMS upload directories or disposable hosting. The ML classifier strongly indicated maliciousness, and the link farm structure suggests an attempt to manipulate search engine results or redirect users to potentially harmful sites. No scripts were extracted, limiting the analysis of direct execution capabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

Heuristics 5

  • 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://lycee-elm.org/userfiles/file/68896069405.pdf In PDF document text
    • http://srsheicha.com/uploadfile/file/12344571359.pdfIn PDF document text
    • http://syarmarka.ru/userfiles/files/nidugukoremu.pdfIn PDF document text
    • https://bawwabatrizq.com/userfiles/file/litotuzutejo.pdfIn PDF document text
    • https://afriqueitnews.com/wp-content/plugins/super-forms/uploads/php/files/1cf1524a0f8dbd01969576a68360d777/52088987882.pdfIn PDF document text
    • https://dichvuketoanvn.org/uploads/files/29306966038.pdfIn PDF document text
    • https://al-wesam.com/userfiles/files/gebojar.pdfIn PDF document text
    • https://pk-kuepfer.ch/ckfinder/userfiles/files/zavolobepepoto.pdfIn PDF document text
    • https://deshpanday.com/ckfinder/userfiles/files/mofugixopuse.pdfIn PDF document text
    • https://jdbailbonds.com/wp-content/plugins/super-forms/uploads/php/files/536f217647633e124b5fbdab801a100b/666111681.pdfIn PDF document text
    • http://voijin.com/userfiles/files/tezega.pdfIn PDF document text
    • https://limmaginebistrot.com/file/60369431777.pdfIn PDF document text
    • https://fertilizergranulatorprice.com/d/files/jaxirafevudu.pdfIn PDF document text
    • http://vaness-sens.fr/ckfinder/userfiles/files/76647350644.pdfIn PDF document text
    • http://cityhelps.org/clients/6/61/61afa7a028a8e04f14432b0fece6f2b0/File/30524787810.pdfIn PDF document text
    • http://dok-vo.ru/userfiles/file/sonagab.pdfIn PDF document text
    • http://trackeg.com/en/wp-content/plugins/formcraft/file-upload/server/content/files/160877ff56c365---72784241064.pdfIn PDF document text
    • https://grand-forge.ru/wp-content/plugins/super-forms/uploads/php/files/0033fc0f2d05ac4bc1eb4ac7bf84b34a/gizib.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/160756eade28a5---tafaropegu.pdfIn PDF document text
    • https://mkting.com.co/wp-content/plugins/super-forms/uploads/php/files/9de05ad633bc2d2851250e6b4567b80e/43088370504.pdfIn PDF document text
    • https://precisionautoandac.com/wp-content/plugins/super-forms/uploads/php/files/bc159b13ae8e15b82b4312720f8c4ad5/metopovob.pdfIn PDF document text
    • http://2478.ru/admin/ckfinder/userfiles/files/61191727242.pdfIn PDF document text
    • http://ibshop.gr/uploads/_uploads/files/21502107199.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=will+there+be+a+michael+vey+book+8PDF 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_off0000e8b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8B2 10836 bytes
SHA-256: a5899fe46052042437a16da95114b8646bc0547de50c19a0eaa38a1bb63e0e99
font_01_sfnt_off000101c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101C9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000119db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119DB 16840 bytes
SHA-256: 0cc32263bcb58ef6e0bd1c03d4a7d47d95979361061bb23fb50c3a47931845ab