Malicious PDF — malware analysis report

Static analysis result for SHA-256 901232726822a1b2…

MALICIOUS

PDF

68.2 KB Created: 2021-06-03 22:51:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: e18d9116c2cf853fc5e2c3acefb897fa SHA-1: 57bf61084545284b94b87b798fbc7ed3eb2c3d23 SHA-256: 901232726822a1b21dfba44d7d900ffe34b23bfb39a07ddf6f03ac3d19d867cc
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, many hosted on disposable domains, suggesting a link farm or phishing operation. The document body, though heavily obfuscated, appears to reference 'Cambridge english first practice tests free', a common lure for educational phishing scams. The presence of external URIs and the link farm heuristic strongly suggest the document's primary purpose is to redirect users to potentially malicious websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://nipisod.ru/123?utm_term=cambridge+english+first+practice+tests+free PDF link annotation
    • https://sigudajofabi.weebly.com/uploads/1/3/4/6/134679089/motufav-bexes.pdfIn PDF document text
    • https://goromezamoko.weebly.com/uploads/1/3/4/7/134753948/mezonanufe.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4371814/normal_603fe86479bc1.pdfIn PDF document text
    • https://sesuwulot.weebly.com/uploads/1/3/1/4/131438847/xunagodu.pdfIn PDF document text
    • https://bifutizuwosedi.weebly.com/uploads/1/3/4/6/134645412/loxuvirade.pdfIn PDF document text
    • https://fefokepixax.weebly.com/uploads/1/3/1/4/131452923/kanam.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4482424/normal_605bc236757ce.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4426954/normal_5fdd342c666e9.pdfIn PDF document text
    • https://zibozofebar.weebly.com/uploads/1/3/0/7/130740265/fisatixi-zetobamemifito-biwewube-kajanapote.pdfIn PDF document text
    • https://jetireduru.weebly.com/uploads/1/3/1/4/131453335/6597700.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4385410/normal_600a3e5015941.pdfIn PDF document text
    • https://mirexoxufi.weebly.com/uploads/1/3/0/9/130969656/6048884.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4381544/normal_606d3f8651603.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4408002/normal_5ff023da66c85.pdfIn PDF document text
    • https://shop.swiss-exams.ch/produkt-katIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/9a8adaf5-7f68-4728-bb37-454234b3866e/xuramawusufen.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b956377c-786f-4c05-b89a-98cdf84d1c21/53814590926.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d399b282-4358-41c5-85fb-72266653b0af/easy_mango_smoothie_recipe_without_yogurt.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/23d1540d-6740-416a-b28b-74b48d2efd11/ocarina_of_time_master_quest_walkthrough_dodongos_cavern.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a66c6bce-6f3c-4ef3-b25f-b7c9b6ce11ec/webezowuvibafukomanigi.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_off0000cdc8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDC8 5612 bytes
SHA-256: 217759c6e8ab5b4dc4c71c85560f4793be48412cafb5654d5c0153ae378367af
font_01_sfnt_off0000e0aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0AA 10140 bytes
SHA-256: e6101dcb9663e187d2c7b81bc150ed36c7a4540f0afad9e3f7d54725c0c09acb