Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf9386d8904bc461…

MALICIOUS

PDF

69.6 KB Created: 2021-10-03 12:46:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: a40c900983ff98e2e0b41a25b08c35f1 SHA-1: a6b8fc7bad77278667ecca0b52f75b6cf69bc00c SHA-256: cf9386d8904bc461a2420a32c2ff8baeaa2acdf9a5f9753674e0973c91ff803c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1055.012 Process Injection T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which are part of a link farm hosted on compromised websites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of multiple external URIs and link farm heuristics points to a tactic of redirecting users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://catamma.ru/uplcv?utm_term=crosswords+for+elementary+students PDF link annotation
    • https://triangle-electronics.com/assets/userfiles/file/tikorililoxi.pdfIn PDF document text
    • https://edukiya.com/wp-content/plugins/super-forms/uploads/php/files/942a4da4431e62e3279a704f77804ab4/navomulegupemaj.pdfIn PDF document text
    • http://nhactheducthammy.com/upload/files/jeniseravavutetapen.pdfIn PDF document text
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/6kj6r94rakkjfmtmu6oh33p2l0/mukazojipapopudo.pdfIn PDF document text
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/161394eb9b4a05---tilebufitux.pdfIn PDF document text
    • http://sherwoodchambergolf.org/ckfinder/userfiles/files/37762173574.pdfIn PDF document text
    • http://avvocato-callegaro.it/public/file/zosatewimipibubixufit.pdfIn PDF document text
    • http://bouwbedrijfansing.nl/userfiles/file/92747849386.pdfIn PDF document text
    • http://kingswaytyres.com/project/kingsway/uploads/file/35085745602.pdfIn PDF document text
    • http://studiovalecchi.it/userfiles/files/74172784659.pdfIn PDF document text
    • http://poddertradingandindustries.com/userfiles/file/komus.pdfIn PDF document text
    • http://tiszaladany.hu/upload/file/20863890635.pdfIn PDF document text
    • https://dimensionshoppe.com/alpha/ckfinder/userfiles/files/kesizodurirejirekum.pdfIn PDF document text
    • http://4darchitecture.org/img/all/92517842416.pdfIn PDF document text
    • http://myapartment.de/web/editor/files/76911835088.pdfIn PDF document text
    • https://ccveg.org/wp-content/plugins/super-forms/uploads/php/files/mhgabetiucnajpfvcjgkkfd80v/84631004999.pdfIn PDF document text
    • http://themetamorphoseprogram.com/userfiles/file/55326066271.pdfIn PDF document text
    • https://smgbid.com/ckfinder_userfiles/files/ligavovefotanadanafi.pdfIn PDF document text
    • http://alidongdong.coco1490.com/upload/file_folder/file/17329922700.pdfIn PDF document text
    • https://terminarz.online/kosmetyczka/krakow/files/viwibawubajijugojupojozuv.pdfIn PDF document text
    • http://zonweringbelgie.eu/ckfinder/userfiles/files/17849016545.pdfIn PDF document text
    • https://www.aaptuk.org/ckfinder/userfiles/files/vijedajegalazos.pdfIn PDF document text
    • https://sharmtocairo.com/userfiles/files/26005920777.pdfIn PDF document text
    • http://suachuaspa.com/upload/images-content/files/66798937325.pdfIn PDF document text
    • 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_off0000b238.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB238 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ca4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA4A 14860 bytes
SHA-256: 3d02be5d53550710b335ab65eb05e47f18c0d26f26dd90e33d962c856d812330
font_02_sfnt_off0000ef85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF85 10752 bytes
SHA-256: 56c82320696380caeca16e6687f51f9e6a360dfbcecf6b3c91304f6119faf547