Malicious PDF — malware analysis report

Static analysis result for SHA-256 50d766bcf114b038…

MALICIOUS

PDF

73.6 KB Created: 2021-05-16 23:35:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-16
MD5: 384c217844716be97bb8b4d276e72561 SHA-1: b446c03e1634aeac8ac3e6c8a138aa520faf950c SHA-256: 50d766bcf114b03875e9d9beafe971692f701f3d0821c470380f173a53d2db49
196 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to Weebly-hosted PDFs, suggesting a link farm or SEO poisoning tactic. The primary URL, https://kuzutuzo.ru/strik?utm_term=elkay+single+drinking+fountain+specs, is identified as a redirector likely used for phishing or malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent, classifying it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://kuzutuzo.ru/strik?utm_term=elkay+single+drinking+fountain+specs PDF link annotation
    • https://bawapumur.weebly.com/uploads/1/3/4/4/134466187/5a776d01830da0.pdfIn PDF document text
    • https://botasapozav.weebly.com/uploads/1/3/1/6/131607984/sekanikif_xumifeligatut.pdfIn PDF document text
    • https://ruwevupezo.weebly.com/uploads/1/3/4/0/134013147/nosogis.pdfIn PDF document text
    • https://sobiwololisa.weebly.com/uploads/1/3/0/9/130969717/2fcdf618e06c.pdfIn PDF document text
    • https://jivetigaforivuj.weebly.com/uploads/1/3/4/3/134350389/fitavurawo-wopaxug-butozi-supopajifuf.pdfIn PDF document text
    • http://farotosinotom.mywebcommunity.org/advantages_and_disadvantages_of_vapour_absorption_refrigeration_system.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://9eb5ee95-128e-4115-bcd6-d8db8525ce49.filesusr.com/ugd/9904c2_e52cff4bca2b4533a08220239f6bd640.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/nitizobuv/tigagesuzokowulo.pdfIn PDF document text
    • https://83d7d1d1-3661-4158-a2cc-78aa4aa39d08.filesusr.com/ugd/163759_719640760ff04c4881b9702b553dd717.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/paxuvagal/41495526070.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a9b4dacf-433a-46c0-9864-f21423f147f9/vovekakof.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/43e1bf64-2854-4907-8fc2-1c2fcf71f404/vokivulavuroxed.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0ec64618-7d51-4312-8ecd-08039d697ce7/lexujigipesafuzabopijip.pdfIn PDF document text
    • https://s3.amazonaws.com/najipavez/77825697326.pdfIn PDF document text
    • http://mifofoxidil.onlinewebshop.net/bnf_online_2020.pdfIn PDF document text
    • https://s3.amazonaws.com/bidurudilidujug/27652838676.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4c6400e2-3504-4c2c-a919-45e7d079763b/how_to_change_background_of_a_photo_in_corel_paint.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_off0000ded2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDED2 5444 bytes
SHA-256: fc0f9fb7ac43300941e14d032f161deac46b396e489df832cdb0c7363008dacc
font_01_sfnt_off0000f17c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF17C 11304 bytes
SHA-256: 61928de78675745511231fb0880c5eb59a560beb4d1463dcbd73a0d442e98648