Malicious PDF — malware analysis report

Static analysis result for SHA-256 7151853e83a76c8d…

MALICIOUS

PDF

88.9 KB Created: 2021-06-11 02:58:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: a0a825d8c2e4917ec57384a85e89a949 SHA-1: 05f60f36cdbd3c052e96ed54495aa7b89cc6b869 SHA-256: 7151853e83a76c8d6fc8eba956f82c928c51f5ebf4a7b47de823b3cdbe66b0cf
126 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many hosted on disposable domains, indicating a link farm. The embedded content, though heavily obfuscated, suggests a lure related to 'speech act theory' to drive traffic to these links. The ML classifier strongly flagged this PDF as malicious, and the presence of numerous external URIs supports the conclusion that this document is designed to redirect users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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://allytemp.ru/pbw?utm_term=types+of+speech+act+theory PDF link annotation
    • https://sogazefod.weebly.com/uploads/1/3/4/0/134000298/pobogemezeseporu.pdfIn PDF document text
    • https://xevogivuzu.weebly.com/uploads/1/3/5/3/135350373/bivag.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4446497/normal_601ec72e9fd6f.pdfIn PDF document text
    • https://kitetunevoneg.weebly.com/uploads/1/3/4/7/134703129/jujamado-migukawero.pdfIn PDF document text
    • https://diminulagiv.weebly.com/uploads/1/3/4/4/134489960/7432260.pdfIn PDF document text
    • https://dukinuvofipul.weebly.com/uploads/1/3/2/7/132711936/zonobejepigu-moxogokisu.pdfIn PDF document text
    • https://finibolamojirum.weebly.com/uploads/1/3/5/3/135341575/f84bd8de264387.pdfIn PDF document text
    • https://fexinunob.weebly.com/uploads/1/3/4/4/134432760/tibibodoresu.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4373502/normal_5fe018eb4bad4.pdfIn PDF document text
    • https://fejalunaruxepiv.weebly.com/uploads/1/3/4/4/134489653/8711057.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4458132/normal_601cdbcd476ff.pdfIn PDF document text
    • https://sopifowa.weebly.com/uploads/1/3/2/6/132681690/mixajaxubegun.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4384634/normal_603c401d89849.pdfIn PDF document text
    • https://pugubitef.weebly.com/uploads/1/3/5/3/135302221/tutagorabe.pdfIn PDF document text
    • https://tepupusaf.weebly.com/uploads/1/3/4/5/134585026/496194.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://gejigavowule.pbworks.com/f/functional_strength_training_workout_routines.pdfIn PDF document text
    • http://dibesusajob.pbworks.com/w/file/fetch/144627051/lerekexesomabiwebuso.pdfIn PDF document text
    • http://zabodovojif.pbworks.com/f/mcafee_antivirus_free_serial_key.pdfIn PDF document text
    • http://nilanom.pbworks.com/f/como_agua_para_chocolate_english_translation_chapter_2.pdfIn PDF document text
    • http://dipoziw.pbworks.com/w/file/fetch/144451980/6.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00012059.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12059 5124 bytes
SHA-256: 87b9dec26a8c8d35311b01254a775685beddf125cdbe58eaeecb66b3e8501293
font_01_sfnt_off000131cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x131CF 10676 bytes
SHA-256: 6c4101e5496adde0155a3703804b4416da82292d923dab95aaee95739fe5fd3c