Malicious PDF — malware analysis report

Static analysis result for SHA-256 51ad441e44589570…

MALICIOUS

PDF

82.5 KB Created: 2021-09-10 01:09:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: fee27b18583dd792a6220eb223eaa419 SHA-1: 5c033dbab51118ae8f8849e70c174524d3089dbe SHA-256: 51ad441e4458957036ee216479c9b835c97bdb0b755a8fde12454576bd590b1a
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and contains embedded JavaScript. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • 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://permanentnimakeup-brno.cz/userfiles/files/segero.pdf In PDF document text
    • https://trystsalonri.com/images/file/nataxutapipamogasi.pdfIn PDF document text
    • http://penzion-u-zamku.cz/files/file/gezarofemuxiwifuguzer.pdfIn PDF document text
    • https://endeligmandag.no/e-brev/data/div/45467658582.pdfIn PDF document text
    • http://exosushi.com/uploads/files/21306342358.pdfIn PDF document text
    • http://consol.hu/images/uploadedimages/file/3643496505.pdfIn PDF document text
    • https://majubesar.info/contents/files/jugurefulag.pdfIn PDF document text
    • http://ne-moloko.ee/wp-content/plugins/super-forms/uploads/php/files/fe2c773c5b93863e6aee20b9bb823afb/kurerel.pdfIn PDF document text
    • http://esipro.fr/userfiles/file/zorafon.pdfIn PDF document text
    • http://thebankcardservices.com/uploads/files/bovagubimoraxijo.pdfIn PDF document text
    • https://uslugiinzynierskie.com/eurostyl/photos/file/89923285633.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/161342b70070d9---23032251574.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/d7fe06ec986ec7b180bb7e989b934c7e/58716030837.pdfIn PDF document text
    • http://aostavet.it/userfiles/files/wamuvobox.pdfIn PDF document text
    • http://ingmarcofaedi.com/userfiles/files/19171242416.pdfIn PDF document text
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/5okg8p3s3ln0r7pf63alv09lm7/96698326757.pdfIn PDF document text
    • https://podgoricki-klub.me/userfiles/file/tibivumisezodebuxowi.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1613966b4114e5---47453224151.pdfIn PDF document text
    • https://tarsiman.ee/files/file/dapejuzalavowufe.pdfIn PDF document text
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612ed3e181826---310875018.pdfIn PDF document text
    • http://tipkeo.com/js/ckfinder/userfiles/files/94003820410.pdfIn PDF document text
    • http://chothuexehochiminh.com/userfiles/file/xukipokajuromiz.pdfIn PDF document text
    • http://profisystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161338d3b55eed---58107491453.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=mt+gambier+buy+swap+sellPDF 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_off0000dd6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD6E 10804 bytes
SHA-256: 6076b482142a3a86b692d5af04910a9ee6bf06b64cc9a7ba59296a74aa62285b
font_01_sfnt_off0000f63a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF63A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010e4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E4C 17908 bytes
SHA-256: cde9043808ea927a410e73686ca3e8a0295be0fe8eedcc6b10f4dcfe44a93a1e