Malicious PDF — malware analysis report

Static analysis result for SHA-256 5edd19a101251b4e…

MALICIOUS

PDF

76.2 KB Created: 2021-09-11 10:25:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 491832b54a95b5cf6db6be205e24bab8 SHA-1: eb84e8ae1330a724dab687a5e643c39bc2fe6e2c SHA-256: 5edd19a101251b4e1a13858c3de60ad8401fbe8e39da9c4b29dcab3bc4fc224b
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains numerous links to external websites, many of which are hosted on disposable domains and appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. While no scripts were directly extracted, the PDF structure and heuristic firings suggest it's designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://fujieshubao.com/zk/UploadFile/file/2021090607224173499.pdf In PDF document text
    • http://dispensapertutti.com/userfiles/files/18180497273.pdfIn PDF document text
    • http://pomocnaukowa.net/Upload/file/koxelebopulodepap.pdfIn PDF document text
    • http://deurenhanger.nl/userfiles/file/51289551149.pdfIn PDF document text
    • http://pierrevillers.fr/mairie_files/file/detitel.pdfIn PDF document text
    • http://ambulatorioveterinariovianello.eu/userfiles/files/21313432757.pdfIn PDF document text
    • http://www.hangmandigital.com/files/file/87310322545.pdfIn PDF document text
    • https://akamercedes.com/images/uploads/files/24559966116.pdfIn PDF document text
    • http://nurugelexport.com/ckfinder/userfiles/files/funuvoraresedewimav.pdfIn PDF document text
    • http://optimumnieruchomosci.pl/uploads/userfiles/files/27441915128.pdfIn PDF document text
    • http://messtores.ca/fck_user_files/file/xakobadazitufeki.pdfIn PDF document text
    • http://frutapac.com/ckfinder/userfiles/files/ripixisi.pdfIn PDF document text
    • http://abaj.cz/UserFiles/File/96666198669.pdfIn PDF document text
    • https://toptenstudy.com/upload/files/BodyFile__613753A572BF3.pdfIn PDF document text
    • https://popa.com.br/wp-content/plugins/super-forms/uploads/php/files/1959f7979150be7f1ef80bd9ad71db7d/49202842373.pdfIn PDF document text
    • https://akrmedia.no/ckfinder/userfiles/files/56172148435.pdfIn PDF document text
    • http://local-minicab.com/survey/userfiles/files/povikapepepikitategej.pdfIn PDF document text
    • http://landpas.pl/upload/file/8334472328.pdfIn PDF document text
    • http://honeystraw.com/uploadfiles/file/pubotixivemewom.pdfIn PDF document text
    • http://15449010.com/FileData/ckfinder/files/20210902_9E254AEB22EB091A.pdfIn PDF document text
    • http://jandenzobv.com/image_uploads/file/duguratokimuf.pdfIn PDF document text
    • http://oticonshop.com/ckfinder/userfiles/files/gavarirotapu.pdfIn PDF document text
    • http://lpc2529.com/piceditor/file/pukovepebikosu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=how+to+hide+text+messages+in+androidPDF 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_off0000c54a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC54A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dd61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD61 10828 bytes
SHA-256: 56cc5ecba581e950ec9e04e9df36047a05fb72f2dadda6eea5f66ad42188dbf5
font_02_sfnt_off0000f600.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF600 17648 bytes
SHA-256: 8e5281ee25eb1868a0c79e9b20b611b8b7c3b6305e310fd2883cb847acfe5c30