Malicious PDF — malware analysis report

Static analysis result for SHA-256 f9b1530c1eab4091…

MALICIOUS

PDF

91.4 KB Created: 2021-06-25 19:52:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fa5babf42f9524a5b1177248f0506cf5 SHA-1: 3be442a18e3ddc4c8f0d96e37682bbc0e4d6f265 SHA-256: f9b1530c1eab4091d90ca2700aa3cc3634ca7271135418ee56224bbe92c49f8c
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external resources, many of which point to compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the heuristic findings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 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://oiweld.com/wp-content/plugins/super-forms/uploads/php/files/023904dcd2059fcdbdff33086df422e8/tupasifogovafokolavaxipan.pdf
    • https://gw21.ch/uploads/userfiles/file/28336698636.pdf
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/160846a71e6d99---37376660291.pdf
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/160954d5c85a34---gofiravo.pdf
    • https://www.alphaveneers.com/wp-content/plugins/super-forms/uploads/php/files/2822dd409d1b3e79469bc85a811cd7a1/gobogo.pdf
    • http://kowel.com/ckfinder/userfiles/files/1622295699.pdf
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b0eb2d8d91---18992930848.pdf
    • http://obasekiestates.com/UserFiles/file/gevigadepivesogunar.pdf
    • http://www.ellisrasbetonwerke.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607a18b1ef040---nogivarivomejaneroto.pdf
    • https://weblative.com/wp-content/plugins/super-forms/uploads/php/files/8c7runv8mu1q6k03dqmbr97qtn/26096616236.pdf
    • https://www.tifdip.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d98ed3595d---30336913687.pdf
    • http://ahcxdq.com/uploads/file/112348378287.pdf
    • http://kleinschaden.expert/userfiles/file/supitezubusezuvepafa.pdf
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b9fdefd1999---tagezolideduzogap.pdf
    • https://fenixfalt.com/userfiles/file/muboziwusosaxosapodivuwus.pdf
    • https://benjamindreyer.com/wp-content/plugins/super-forms/uploads/php/files/1183c6fc3813403d488531c22e06a5a9/37951415182.pdf
    • https://www.emma-solutions.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608fb46808e44---gamafilibiv.pdf
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a097b878c64---57228026337.pdf
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/160b4bb7d0c2a8---75852745281.pdf
    • http://koszyczarek.pl/userfiles/file/82479215142.pdf
    • https://www.getfitcrew.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7d3c03f628---xudawamamot.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=who+is+ondreaz+lopez+dating
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ea6c.bin
dc2d77f167dc53bec337fe5b424fba685bdf89657bd49624d7cbfab74f24c42c
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA6C 17700 bytes
font_01_sfnt_off00011965.bin
421036bc97cc9a4bdba7cffc53a1d0fc04acde26eb4480bb0de42f1a825d6aad
pdf-font-stream PDF embedded font (sfnt) at offset 0x11965 10724 bytes
font_02_sfnt_off000131d1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x131D1 16792 bytes
font_03_sfnt_off000149e2.bin
45647295bf3e6975917d2c46c854a2f040b6d2f4fa9dfc4d8f9276b78401693b
pdf-font-stream PDF embedded font (sfnt) at offset 0x149E2 16396 bytes