Malicious PDF — malware analysis report

Static analysis result for SHA-256 394dd83c1a9920f0…

MALICIOUS

PDF

83.4 KB Created: 2021-04-02 02:09:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-10
MD5: bdeb1c5a7bbb4a9c05d60e4daef0ef5b SHA-1: 0e115cdc80ec5d4d373104e49c666373bb9d0d12 SHA-256: 394dd83c1a9920f01977ed82428cdb2df8ca47d948682a01c7f0015f7203103e
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of external links, suggesting it functions as a link farm, potentially for SEO manipulation or to direct users to phishing sites. The document body, though heavily obfuscated, contains references to calculus books and the wkhtmltopdf tool, aligning with the link farm's theme. No scripts were extracted, but the presence of numerous external links points to a redirection-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://golowaki.ru/award?keyword=calculus+mathematics+book+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4455208/normal_603888c3e4560.pdfIn PDF document text
    • http://narovomesizi.medianewsonline.com/40419874230.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4473049/normal_5fe4dafb2a0f5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4373527/normal_6009e99220415.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4486036/normal_5fee967373520.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4384323/normal_605924fd8c9cc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4409110/normal_6033dcba46020.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366335/normal_601297697d994.pdfIn PDF document text
    • http://tidirakozodawon.getenjoyment.net/72104603189.pdfIn PDF document text
    • http://fadewujetenuve.mywebcommunity.org/can_rahu_be_atmakaraka.pdfIn PDF document text
    • http://dududuw.mypressonline.com/wunavaza.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4378848/normal_605c933ddb7c6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4407057/normal_603d55458c0cf.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://sarutufasiko.atwebpages.com/binomial_cdf_and_difference.pdfIn PDF document text
    • https://s3.amazonaws.com/puretulenuza/81581634222.pdfIn PDF document text
    • http://xinifaduzinuvu.onlinewebshop.net/bovetogibiwakerolazujajej.pdfIn PDF document text
    • https://515a9975-19bb-4041-9922-7b1a45dc692c.filesusr.com/ugd/f34823_67838b7501294410a4ed2d23e355af39.pdf?index=trueIn PDF document text
    • http://zulolabopel.myartsonline.com/25381330460.pdfIn PDF document text
    • https://s3.amazonaws.com/jimugivos/fuketonomezuvup.pdfIn PDF document text
    • https://c1bbde11-5cda-4f7c-8b74-b2fe90b484f5.filesusr.com/ugd/1c8c6c_70d24ef948c6420dab882dcfa879212e.pdf?index=trueIn PDF document text
    • https://c580675e-8888-491d-8c80-3106eaac86fb.filesusr.com/ugd/c8a981_dc4e77a4e3ec44cb97ec5075bf117166.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/mudurixo/rancilio_silvia_espresso_machine_pro.pdfIn PDF document text
    • https://s3.amazonaws.com/jafujasiwetid/lotejenuvewarore.pdfIn PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fb88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB88 5300 bytes
SHA-256: ed1a0b91d1a7b426b39c44f0beaf20846b68c375cfe3c955984d97fa410c2f6d
font_01_sfnt_off00010d90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D90 10648 bytes
SHA-256: 18cb7bc406d33a59b94544d43c541a09f45b2c8d65055944ba7296d60ab43b0e
font_02_sfnt_off000131f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x131F2 4324 bytes
SHA-256: 1062cd8ddf90f4344fa193b395386d5669df1a952e5759311ca261a71931f361