Malicious PDF — malware analysis report

Static analysis result for SHA-256 31e661de3be510e9…

MALICIOUS

PDF

87.5 KB Created: 2021-09-22 11:00:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 79c9a11ad7d17f51c2a52f9a9b48c093 SHA-1: a8ae4d54f3cfc99a0451b6c6ac4dfa6dcb55c15e SHA-256: 31e661de3be510e90b2239c1e0c2ee4ef238d578beb7fe0f5dcfe86cb7188b8e
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm pointing to compromised websites. The PDF contains numerous links to external sites, many of which are hosted on disposable domains or appear to be part of a link farm strategy, suggesting an attempt to redirect users to malicious content. The presence of external URI heuristics and compromised CMS upload links further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://0985028898.kad.tw/kads/ckfinder/userfiles/files/lurazuzowizasaxulinu.pdf
    • https://sibois.eu/userfiles/file/26409399894.pdf
    • http://brava-ekb.ru/userfiles/file/fitubederawun.pdf
    • http://radis-rrl.ru/userfiles/image/mepekupositukajogagofuse.pdf
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/161414ceca72be---98258248565.pdf
    • http://kasaitogo.com/uploads/files/55846088756.pdf
    • https://fengshan-zhennangong.org/upload/ckfinder/files/28689195189.pdf
    • https://ardiinerkh.mn/uploads/userfiles/files/98244943002.pdf
    • https://atputasbaze.lv/images/userfiles/files/10974945662.pdf
    • http://jingmingtai.com/filespath/files/20210912211929.pdf
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/16139a393d3711---37872465133.pdf
    • http://littlepearlbooks.in/data/eimages/file/ziweloferuputun.pdf
    • http://basketaci.cz/UserFiles/File/fexadewu.pdf
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/16141ca4c217dc---puxogupaxidejirufafedi.pdf
    • http://fotofolliasanlazzaro.it/userfiles/files/sugup.pdf
    • https://shopexpert.com/app/webroot/files/userfiles/files/kopoki.pdf
    • https://evergreencans.com/userfiles/file/12364859977.pdf
    • http://milcontabil.com.br/wp-content/plugins/super-forms/uploads/php/files/otlgbo0gsqmu4s42rcbipr8lk7/dalemebezixanakevudoweto.pdf
    • http://go-pxl.com/uploads/files/48541346545.pdf
    • http://amongelite.com/ci/userfiles/files/89150028706.pdf
    • http://dogalakustik.com/depo/sayfaresim/file/95698621936.pdf
    • https://pjkconstruction.ca/images/file/55963011398.pdf
    • http://pawsandtiaras.com/ckfinder/userfiles/files/50316729094.pdf
    • http://proclima-membranes.ru/userfiles/file/ropuzurogidu.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=yukari+persona+3+dancing
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e883.bin
bf5774befe0794b6275bea60366d83b686208110ccc224f69e939d727df7ade7
pdf-font-stream PDF embedded font (sfnt) at offset 0xE883 20836 bytes
font_01_sfnt_off00011f29.bin
d01d5ac4bd411e794e92ec1e81c3b67e6c95aa939e2d27c9259555c3cf053ab3
pdf-font-stream PDF embedded font (sfnt) at offset 0x11F29 10892 bytes
font_02_sfnt_off00013848.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13848 16792 bytes