Malicious PDF — malware analysis report

Static analysis result for SHA-256 a40abb839005d30e…

MALICIOUS

PDF

71.0 KB Created: 2021-09-27 09:08:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 769456e01793b6e46467d1aa61122fc7 SHA-1: 743f14e8e74a672c4e35b19a9e7bf38a253bd1c7 SHA-256: a40abb839005d30e795477ecebed29e404c45309d5782e291dc8f867397b4102
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs pointing to a link farm, a common tactic for phishing or distributing further malware. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically flags this behavior, suggesting the document is designed to redirect users through multiple disposable domains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • 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 http://abwingsbuffalo.com/uploads/files/mowakuborujunegodizuxevo.pdf In PDF document text
    • http://aedjtjdshbf.pretty-match.com/upload/files/2255431750.pdfIn PDF document text
    • http://tv-kitchen.ru/files/files/10079178591.pdfIn PDF document text
    • https://korzayithalat.com/spot/admin/fckeditor/userfiles/file/63472014970.pdfIn PDF document text
    • https://silky.ae/images/bulk_images/files/begirijom.pdfIn PDF document text
    • http://atel-j.nl/uploads/files/sebogunaborenarugafus.pdfIn PDF document text
    • http://cn-daomeng.com/upload/userfiles/files/2f07a0af2866717abbb9fa0b27320412.pdfIn PDF document text
    • http://ck-kutnahora.cz/gais/image/file/812704138.pdfIn PDF document text
    • https://nepalihemp.com/ckfinder/userfiles/files/kemiwoxuwuxom.pdfIn PDF document text
    • https://artbynela.com/uploads/file/16495346783.pdfIn PDF document text
    • https://mystruggle.uk/indigo/ckfinder/userfiles/files/rizojuwow.pdfIn PDF document text
    • http://deleeuwputten.nl/site/data/ws/files/13064711129.pdfIn PDF document text
    • http://americasbestwingsbeltsville.com/uploads/files/vilid.pdfIn PDF document text
    • http://elencostruzioni.it/userfiles/files/53606299484.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613f6788a0b31---nalofaparolete.pdfIn PDF document text
    • http://rts-3.ru/upload/files/23286571408.pdfIn PDF document text
    • http://nollve.com/img/editor/image/file/70431301493.pdfIn PDF document text
    • https://bhiringisamsankalimandir.org/userfiles/file/62220834066.pdfIn PDF document text
    • http://lagrupacio.cat/file/gijudigogepef.pdfIn PDF document text
    • https://aradovan.com/userfiles/file/tewelubizo.pdfIn PDF document text
    • https://www.dooleysnaturalgas.com/ckfinder/userfiles/files/9906567452.pdfIn PDF document text
    • http://rcp-ranstadt.us/files/55442815554.pdfIn PDF document text
    • http://laxycoffee.com/upload/files/66844055339.pdfIn PDF document text
    • http://bbbo.handyfriendship.com/upload/files/raxorigojoletotobefiju.pdfIn PDF document text
    • http://revucue.com/ckfinder/userfiles/files/nabijidenesejolelim.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=fps+games+for+android+with+controller+supportPDF link annotation
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b38d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB38D 15828 bytes
SHA-256: 9531ccb787bc6101d82871347012c4aed54a33c702acd1ec829f1b9f7d0a4156
font_01_sfnt_off0000dbae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBAE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f3c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3C5 11228 bytes
SHA-256: ac90c582748bb5ffd7a47b68d69bbf314cbeb278eb8d8f7ec6a76914c60feeea