Malicious PDF — malware analysis report

Static analysis result for SHA-256 21eb98fc7459366a…

MALICIOUS

PDF

79.8 KB Created: 2021-09-16 23:34:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: fc1b5cca55779499da07f722df379678 SHA-1: 3e973e4860afad6f87810000ca4c3b5f963a93f6 SHA-256: 21eb98fc7459366a7c3beaadca6a80e0d5f4a8a80287209a0d8e3846eba4a579
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external PDFs hosted on various domains, indicating a link farm designed to obscure the ultimate malicious destination. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and the high ML score strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the structure points to a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://hotelpenza58.ru/ckfinder/userfiles/files/22179390991.pdf In PDF document text
    • https://nhanloc.net/userfiles/file/41637317386.pdfIn PDF document text
    • https://stthomasorthodoxchurchsouthpampady.com/userfiles/file/57853152508.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1614258d474f65---79486527434.pdfIn PDF document text
    • http://fioredda.com/userfiles/files/tuwironofuxusutori.pdfIn PDF document text
    • https://ceccarmehedinti.ro/userfiles/file/sokukiraxamoso.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/rifureruwuxif.pdfIn PDF document text
    • http://gzafjc.com/uploadfile/files/4634387331.pdfIn PDF document text
    • http://cafegreenwichvillage.com/uploads/files/21498483491.pdfIn PDF document text
    • http://sirmamedia.com/ckfinder/userfiles/files/pibawasovarujugabegipevi.pdfIn PDF document text
    • https://onecre.com/images/content/files/nokotojilexefe.pdfIn PDF document text
    • http://etenindex.nl/images/uploads/94732827650.pdfIn PDF document text
    • https://jamisonfurnace.ca/userfiles/files/45000285532.pdfIn PDF document text
    • http://ambulatorioveterinariosanfrancesco.com/userfiles/files/rumedetivekidafuwisapawo.pdfIn PDF document text
    • http://www.globalnautique.nl/upload/files/forejubadosogoge.pdfIn PDF document text
    • https://www.vignolaweb.it/ckfinder/userfiles/files/7879195052.pdfIn PDF document text
    • http://hjhchem.com/upload/files/71276089385.pdfIn PDF document text
    • http://dc-42351dc5a6b3.prshots.es/uploads/userfiles/1631075178/files/62459319678.pdfIn PDF document text
    • https://landatur.com/files/galeria/files/42717400244.pdfIn PDF document text
    • https://zoldlepes.hu/userfiles/file/ribupanipo.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d2fb568acd---58050422323.pdfIn PDF document text
    • https://xedulichhaiphong.vn/images/news/files/fixezezevejiwoxebutu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=cubed+square+rootPDF 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_off0000d41d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD41D 10416 bytes
SHA-256: 110607354fed16c58c7d9a8bf4d1a6e367982745b534eb459661147ff037012e
font_01_sfnt_off0000ebad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBAD 18064 bytes
SHA-256: c3f6f5a289695b04088898b18a37f219abbeabc7fd022085beab9b634ca90c36
font_02_sfnt_off00011a51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A51 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1