Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7ec239ea8221195…

MALICIOUS

PDF

75.0 KB Created: 2021-06-26 01:09:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6355b1824d531846d92be8d5f1cd908d SHA-1: 7289ce64330a626388ecfbefa5cb120548f3a75c SHA-256: a7ec239ea82211951e2b761c06d19b817917c4ab07ab938209330b41eaeacd65
196 Risk Score

Malware Insights

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

The sample is a PDF document that employs a social engineering tactic, specifically a browser extension or update installation lure, to trick the user into executing malicious code. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded URLs, while some are marked benign, are part of a link farm strategy, and one points to a compromised CMS upload. The document's structure and heuristics suggest it's designed to facilitate the download and execution of further malicious payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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 https://abicecream.ru/ckfinder/userfiles/files/39000181700.pdf
    • http://mdc.ir/ckfinder/userfiles/files/77746149473.pdf
    • http://fortlauderdalelimorental.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c5d0958c31c---disamovafakojawe.pdf
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/7qkmhhpmbr9e32khn9u3q6es4j/16272320726.pdf
    • https://accesoriosalmayor.com/images/userfiles/file/90712065759.pdf
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16083ab3ba7907---13974959207.pdf
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/16078f321f2b93---47867148692.pdf
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/16092697b7d061---66483207629.pdf
    • https://noticky.net/akce/fotky/file/xixelimodifeniwe.pdf
    • http://chekeeh.ir/basefile/chekeehir/files/4884732867.pdf
    • https://bestmiamiturf.com/wp-content/plugins/super-forms/uploads/php/files/5c6a0566604d01999df8bc5bd8829741/35834034197.pdf
    • http://kppzp.pl/userfiles/file/1538206474.pdf
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/n1hfkt3ni2uvddnpjid5kjvqgm/68325005747.pdf
    • https://topclassgreenery.nl/images/file/97531559895.pdf
    • http://pericosrentcar.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16078a74b595d8---45057086865.pdf
    • http://famillespourstarlight.ca/clients/a/a9/a9b42c05011d3bb27e7f7ec2ed30324f/File/39235475375.pdf
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c6dfc87fe51---70432392206.pdf
    • http://allseasonsart.com/uploads/fck_uploads/file/gimivojakexizu.pdf
    • http://k1a.ru/images/files/file/21981046359.pdf
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c9900d4539---22336066640.pdf
    • https://sinhadventure.com/uploads/file/muvafom.pdf
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082a4e942005---22736898208.pdf
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609aa3b9e9114---xusirogotiwilavab.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=pink+panther+easy+piano+pdf
    • 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_off0000c27b.bin
be4eed87970e7c085b44cba60ce15c0f86923630abd4a0e7fed19ca58e5f9a2a
pdf-font-stream PDF embedded font (sfnt) at offset 0xC27B 10756 bytes
font_01_sfnt_off0000db36.bin
99970c2061d467b3e551a8dfda7cba71b120ae2a5e33302352366aa86a64d9af
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB36 16764 bytes
font_02_sfnt_off000106f3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x106F3 16792 bytes