Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7aacc9edb51d957…

MALICIOUS

PDF

84.2 KB Created: 2021-09-09 07:09:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: dab674a6d3cdb7b39aff5cd758642172 SHA-1: 9cd0dd72575c32e8fc617dd62d6d3a49c4a31238 SHA-256: a7aacc9edb51d957b5b15fa9ca62e4bf31b03c66a9c1effc8d3492f16addef13
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution through these links. The document body is unreadable, but the heuristics and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://appchecar.com/ckfinder/userfiles/files/45383363518.pdf In PDF document text
    • https://dailyhondaotomientay.com/upload/files/48488280853.pdfIn PDF document text
    • http://www.mariabeckmann.com/fotos/uploads/files/lotogot.pdfIn PDF document text
    • https://spandoekland.nl/userfiles/file/nutezobuvataxixepizine.pdfIn PDF document text
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/161354deb7efea---fafamufadoxazam.pdfIn PDF document text
    • http://quanhoangtsi.com/upload/quangtri/files/tazunepavibasipovulet.pdfIn PDF document text
    • http://stefanourso.com/public/userfiles/file/29232080795.pdfIn PDF document text
    • http://morebricks.com/ckfinder/userfiles/files/18898733790.pdfIn PDF document text
    • http://sarljarry.com/userfiles/file/30527866872.pdfIn PDF document text
    • http://www.travelwithtaangoo.com/img/file/13018245074.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137ed2d08a50---57245011229.pdfIn PDF document text
    • http://jyjjapan.jp/files/ckeditor/files/koletakoxumigekidafapur.pdfIn PDF document text
    • https://acconpriti.com/ckfinder/userfiles/files/69262741872.pdfIn PDF document text
    • https://serihosting.com/calisma2/files/uploads/72226486801.pdfIn PDF document text
    • https://home-consult.lu/userfiles/files/16238954779.pdfIn PDF document text
    • http://geodeslaboratori.eu/userfiles/files/wisozanoniribozuretafixu.pdfIn PDF document text
    • http://zatacorp.com/upload/files/34207960268.pdfIn PDF document text
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/1c4d5ab7011e196bdf1c8d5b7c38f525/92260010676.pdfIn PDF document text
    • https://partroyfuneralhome.com/partroy/assets/file/39571991614.pdfIn PDF document text
    • http://nwatchonline.com/userfiles/file/14029510376.pdfIn PDF document text
    • https://resonanceacteurs.nl/userfiles/file/kitirologen.pdfIn PDF document text
    • http://dlshixiang.com.cn/ckfinder/userfiles/files/rojikemajon.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=best+android+launchers+for+tabletsPDF 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_off0000e398.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE398 10868 bytes
SHA-256: b4107b66fb2a0bed00890d366a9b38eaf9fe3f197e7a6e459ec1f1e599c6004e
font_01_sfnt_off0000fca2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCA2 17684 bytes
SHA-256: fcd068c5a1ba9820b733b7de218ef650ccf81790efbeebb606b93433c19fa0ce
font_02_sfnt_off00012af4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AF4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1