Malicious PDF — malware analysis report

Static analysis result for SHA-256 52a6c058103c8dba…

MALICIOUS

PDF

78.1 KB Created: 2021-07-02 19:03:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 31263b18a11a0ebd7b9ec82224369440 SHA-1: a0bec8d4f35555782dc492f5d605a51f76e469c8 SHA-256: 52a6c058103c8dba0238bf0609ddc8c549ca287cd3798e3b39655a71e9189bdb
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites, likely to manipulate search engine rankings or distribute further malware. The document body is heavily obfuscated and contains metadata from wkhtmltopdf, suggesting it was programmatically generated.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/1607d2f6b9da78---wemurupedireduribu.pdf
    • http://kondicionery-dolgoprudny.ru/upload_picture/file/vumamukasebebafanaja.pdf
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b4ec1e7fbc---61515746990.pdf
    • https://olmitek.by/wp-content/plugins/super-forms/uploads/php/files/fkbu8fo5ct3k73od9md99gjav2/dipuxuvufa.pdf
    • https://acornschoolcharleston.org/wp-content/plugins/super-forms/uploads/php/files/7cebdacbd603e9234464fd3040c8b729/56044104096.pdf
    • http://nedirajtebosnu.net/userfiles/file/vilazikenugezubiv.pdf
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1608b2435f2f75---91820034736.pdf
    • https://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4e24c9396d---gogusujozirasowonazuke.pdf
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16072c73e95a97---bifijafetutexinafobar.pdf
    • http://katachizu.com/img/news/files/libofupogolozijalibejun.pdf
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab7be6be155---36516940157.pdf
    • http://maekuangudomthara.com/ckfinder/userfiles/files/texinaki.pdf
    • https://law.myvzl.com/wp-content/plugins/super-forms/uploads/php/files/hccbitbjb12tvugm0hmkdnjekf/gotevotidafedasadozijol.pdf
    • http://adance0112.com/upfile/editor/file/wekon.pdf
    • https://aradovan.com/userfiles/file/61602192321.pdf
    • https://www.bluegreenshouseboats.in/wp-content/plugins/formcraft/file-upload/server/content/files/160d665c241eb7---xiregata.pdf
    • https://gtnet-engine.com/ckfinder/userfiles/files/gedowizugilonejusinifa.pdf
    • https://feniks9.ru/ckfinder/userfiles/files/78431352305.pdf
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608462a54106f---vofet.pdf
    • https://3dreamvr.com/wp-content/plugins/super-forms/uploads/php/files/986fec11cd2aae6bb8ff709cc3b23d87/85008641847.pdf
    • http://megalaserasia.com/upload///foduxom.pdf
    • http://msinziniering.com/userfiles/file/rubofabukivotiz.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=funny+puppy+faces
    • 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_off0000d04d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD04D 16792 bytes
font_01_sfnt_off0000e85f.bin
d721db5050d9f8f64aae9cce570b7ee61308054f77a2b286d4d987fc6bfa1b02
pdf-font-stream PDF embedded font (sfnt) at offset 0xE85F 17076 bytes
font_02_sfnt_off00011476.bin
e7af642055c1edc050531a56fe83489bcd359214b6d9f29b52ff60780bd63987
pdf-font-stream PDF embedded font (sfnt) at offset 0x11476 10208 bytes