Malicious PDF — malware analysis report

Static analysis result for SHA-256 8cf94fa026e0332c…

MALICIOUS

PDF

83.3 KB Created: 2021-03-21 07:38:37 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-30
MD5: a606421a21c4843893cdb39e3686ef6c SHA-1: 995c987ddee02f3849fca5325f99611211b5abe4 SHA-256: 8cf94fa026e0332cb6ee6073c15356095879053a37ed744707abcb96fad2ac9e
126 Risk Score

Malware Insights

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

The PDF contains numerous external links, with one prominent URL pointing to a site that appears to be a keyword-based redirector. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The document body, though heavily obfuscated, suggests a lure related to educational content, specifically 'worksheet answers'.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • 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 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://midufefew.ru/wix?keyword=1-5+parent+functions+and+transformations+worksheet+answers PDF link annotation
    • https://cdn.sqhk.co/bujasugawo/iOBjfXP/5916960404.pdfIn PDF document text
    • http://abzac.me/your_choice_restaurant_menuw7ht8.pdfIn PDF document text
    • https://cdn.sqhk.co/buruvalufe/aLjqpjh/real_car_racing_3_game_download.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4373778/normal_6039dc92b593a.pdfIn PDF document text
    • http://particulier-societegenerale.xyz/element_tv_codes_spectrum9ta3s.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369793/normal_6030ad4ee88a2.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4423148/normal_5fdf467ec8f95.pdfIn PDF document text
    • https://cdn.sqhk.co/sativomofij/RowgfLK/55473503162.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4409113/normal_5feb6db68a080.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4373241/normal_60543985718b3.pdfIn PDF document text
    • https://cdn.sqhk.co/jasurisunav/iwihjfC/reversal_time_blade_ninjago.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/wixamupelinere/tojeruran.pdfIn PDF document text
    • https://8b62b971-d575-4461-ae89-9de7a2afac08.filesusr.com/ugd/c5a911_93e94d043ce84163a605dad58520090c.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/dedinavesute/xagujibupadaxe.pdfIn PDF document text
    • https://7c3dd69e-6649-485e-b385-36acc2971cd6.filesusr.com/ugd/cf9ff1_f4e185e2b9cf4cf1a27fbb86f26e4ba8.pdf?index=trueIn PDF document text
    • https://c0b8f06b-4e98-4d3d-89ef-2f08caba629a.filesusr.com/ugd/0c8cc8_cad929735302462fb59269c02aa8e431.pdf?index=trueIn PDF document text
    • https://b5526579-b22d-45a0-8251-9885a72cf3eb.filesusr.com/ugd/0cd019_917d5c39195b4977b342c84a0842edf2.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/tirimofufemukat/xiwubinirufeperesigox.pdfIn PDF document text
    • https://0b21792c-a699-4cf4-8833-5910c6ad58af.filesusr.com/ugd/b0b521_541986ef532e4f6aa5b6ec48ed27010a.pdf?index=trueIn PDF document text
    • https://c09438b0-f1cf-4ade-afa2-d322e048c450.filesusr.com/ugd/313cc6_865178d7bcb845109c533bec3173fe44.pdf?index=trueIn PDF document text
    • https://3176e400-c268-4dc0-8d69-08eae86937f8.filesusr.com/ugd/ea2f88_041064b2436343d8b2a66367c2ab19a8.pdf?index=trueIn 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
    • 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_off0000f006.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF006 5632 bytes
SHA-256: 0430426219ccf907d6687658b2c10915351998682f16a250854f83487fb30378
font_01_sfnt_off00010324.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10324 11456 bytes
SHA-256: a1e4f6bc10de8d4a293c8dec8f71cfa6e56e72dd95ef6a51985009f3bdd160cb
font_02_sfnt_off00012a1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A1B 16092 bytes
SHA-256: f12998e4de2c4add16154aa3061da321808f144478938a8e5b2a68716cc9751c