Malicious PDF — malware analysis report

Static analysis result for SHA-256 31895a289bdb8284…

MALICIOUS

PDF

83.0 KB Created: 2021-05-20 17:09:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: 2f9a68d3528c89b701249924a928975a SHA-1: 2c11eb273d0e0ee04b7181d69fa4f3be94c42e5a SHA-256: 31895a289bdb8284cf68ff2cdc3e46fa69e5f391a23b7d80954b215753a98231
136 Risk Score

Malware Insights

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

The PDF file contains heuristics indicating it is a phishing lure, specifically using an image to redirect users to an external URL. The primary URL identified, https://druttle.ru/strik?utm_term=challenging+catastrophic+thinking+worksheet, is flagged as a redirector. ClamAV detection as 'Pdf.Phishing.Trojan' further supports its malicious nature. While no scripts were explicitly extracted, the PDF structure and embedded URLs strongly suggest a phishing attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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
  • 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://druttle.ru/strik?utm_term=challenging+catastrophic+thinking+worksheet PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4370285/normal_60364bca54468.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369333/normal_60535342e222d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4406170/normal_606b25809ec27.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4391605/normal_603595f1b09c9.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4375203/normal_6005220830934.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4422390/normal_60675fd1baf83.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4502188/normal_5fd91546b351f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4484820/normal_5fd711826a5b4.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4454438/normal_5fffef68d4e67.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4476939/normal_5fdd6f219e149.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4482636/normal_605441b34e2e3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4482858/normal_604dc07a5b1cf.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379969/normal_6036b1990a797.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485801/normal_604dee31eb158.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375196/normal_6018dd99e5541.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/rebomedug/saxukibagafimosasunuwe.pdfIn PDF document text
    • https://s3.amazonaws.com/mupukesunobaga/ejemplo_de_curriculum_vitae_para_trabajo.pdfIn PDF document text
    • https://s3.amazonaws.com/vofadoloves/95124354965.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1dc95557-5f23-418a-b148-30a5b26e90f6/estructura_de_un_texto_descriptivo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bcc5e820-c1e7-4c2f-95c4-0144580d2f58/dexubidowezoxaf.pdfIn PDF document text
    • https://s3.amazonaws.com/xufujofaleki/pmi_lessons_learned_template.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2b4246e8-8db1-4285-b41b-35b6a32ab834/fovojefo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a83fd2f8-e4e9-4d9e-910e-502684934c51/easton_aluminum_arrow_size_chart.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f24fd6f5-2bfc-482e-81e3-706e108486dc/is_the_maze_runner_book_appropriate_for_12_year_olds.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_off000104f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104F6 5256 bytes
SHA-256: 80894c9d3ef60b618c906fe7edc176c4fa7897a56f73627cbb516ab4416c3815
font_01_sfnt_off000116e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116E1 11108 bytes
SHA-256: 12f13269c149d9a287f7c52b2437fb2bca749306a5eb1e78438cfcc945811e6e