Malicious PDF — malware analysis report

Static analysis result for SHA-256 280db0f0c8843f23…

MALICIOUS

PDF

86.7 KB Created: 2021-06-10 21:13:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: c8653c89a8150a70bcdb087dd505b04f SHA-1: 03332317cdad7273ab45916e013762194c51f512 SHA-256: 280db0f0c8843f238e677e05ad3f475a34f911873806c3da2dbbeca4ccbc28a8
156 Risk Score

Malware Insights

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

The PDF document is identified as malicious by ML classifiers and ClamAV, and contains numerous links to compromised WordPress sites. The document body, though heavily obfuscated, suggests a lure related to 'lesson 5.4 answer key 6th grade', indicating a phishing or scam attempt. The embedded URLs and link farm heuristics point to the document's primary function of redirecting users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://ketchas.ru/uplcv?utm_term=lesson+5.4+answer+key+6th+grade PDF link annotation
    • http://vipavtoufa.ru/wp-content/plugins/super-forms/uploads/php/files/1c4bd57e56e873b2828c40f1dae165bd/karadarevapexibinogafetos.pdfIn PDF document text
    • https://jdbailbonds.com/wp-content/plugins/super-forms/uploads/php/files/d5602b44ea8d03407742f9cd457e247c/lomomagifofu.pdfIn PDF document text
    • https://rittenhousesmiles.com/wp-content/plugins/super-forms/uploads/php/files/898efb5911a40c9a45d667bbd6e3b18a/93452069087.pdfIn PDF document text
    • http://beergolfers.com./blog/images/file/1385581400.pdfIn PDF document text
    • https://anfauglir.com/images/file/sezinolimizujogajesabo.pdfIn PDF document text
    • http://zkojicin.cz/userfiles/file/82985926148.pdfIn PDF document text
    • https://www.histoiresdegroupes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a870a4d28b5---zolakekumozosetom.pdfIn PDF document text
    • http://boathousebrokerage.com/userfiles/file/xigijaruxadukepufavu.pdfIn PDF document text
    • http://mu-rrrc.com/userfiles/file/49701978146.pdfIn PDF document text
    • https://www.hamburgeriaagricola.com/wp-content/plugins/super-forms/uploads/php/files/67chvo4cbtq98kle887mah6b5h/bularigoguxezavel.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160867df1ecbb2---midosokuvatir.pdfIn PDF document text
    • https://www.kiakaha.gr/wp-content/plugins/super-forms/uploads/php/files/abjo1n3kdnmgilri9n4dufavjf/vosuteriv.pdfIn PDF document text
    • https://soechi.net/userfiles/file/nazarutumigudot.pdfIn PDF document text
    • http://vudafrique.com/wp-content/plugins/super-forms/uploads/php/files/62f517de4220af77489c3f1855a7a68e/13652696618.pdfIn PDF document text
    • https://lashmakerpro.it/wp-content/plugins/super-forms/uploads/php/files/e3n8lf8k911036ivf1r4ml45r6/87468477362.pdfIn PDF document text
    • http://www.thebetterinsurance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608cec5d69dfc---fupofijelif.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000112d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112D1 5652 bytes
SHA-256: 1b10d6eae487466ee4a13009bd81d51e411865b4211af1a3b6144d6954dbc65b
font_01_sfnt_off00012637.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12637 11584 bytes
SHA-256: 0c0739f3e1ae9b2e6e85ada8da18465a90881f34214d8b3d04a803ff319f4170