Malicious PDF — malware analysis report

Static analysis result for SHA-256 358a8b6e77164b68…

MALICIOUS

PDF

89.5 KB Created: 2021-09-15 11:14:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: ac60d3d3e8f1a63019a626adab181ffa SHA-1: 670f19a8e946a1ad01fa14c0cd08395466fa80de SHA-256: 358a8b6e77164b68a77e7b201c1116e11ef536ccaa58accf7c390834517588c4
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as a phishing trojan and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with multiple URLs pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious sites. The document body was heavily obfuscated and unreadable, providing no direct content-based clues.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9913

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://ptairsupply.com/userfiles/file/wewosezofaniru.pdf In PDF document text
    • http://www.accessibilite-salle-eau.com/ckfinder/userfiles/files/60952265376.pdfIn PDF document text
    • https://akproauto.com/nbloom/fckuploads/file/vudozixose.pdfIn PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/161398d2db5505---nesojupofomu.pdfIn PDF document text
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fcf912fe1f---31094653884.pdfIn PDF document text
    • http://stringquartet.biz/web/images/fck/file/bizalovumozu.pdfIn PDF document text
    • http://bjhtdszdh.com/v15/Upload/file/2021961732302104.pdfIn PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16133f9c3e2fbf---11366878955.pdfIn PDF document text
    • http://madurastones.com/userfiles/file/kerod.pdfIn PDF document text
    • https://mudateconmigo.cl/wp-content/plugins/super-forms/uploads/php/files/344a9a111cd0f3e03ed4fe15b95d170d/67048188522.pdfIn PDF document text
    • http://sea-cruise.ru/ckfinder/userfiles/files/26184196832.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613abb52b0dea---58304458463.pdfIn PDF document text
    • http://savvyais.com/userfiles/file/vukogisepikevuvaf.pdfIn PDF document text
    • http://yuha.be/_files/file/99533794806.pdfIn PDF document text
    • https://ntct-dz.com/ckfinder/userfiles/files/42285117911.pdfIn PDF document text
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613afc23729f3---78189991397.pdfIn PDF document text
    • http://lso-msm.com/userfiles/file/93471847765.pdfIn PDF document text
    • http://exito-opakowania.pl/userfiles/file/31225801293.pdfIn PDF document text
    • http://streetnn.ru/data/upload/ck/files/wunudisifub.pdfIn PDF document text
    • http://taiwan-casters.com/userfiles/file/31008403333.pdfIn PDF document text
    • https://takiminsahada.com/wp-content/plugins/super-forms/uploads/php/files/e38rt3ok042sjt87ues09oq966/puges.pdfIn PDF document text
    • http://ymjgolf.com/file_media/file_image/file/12387906618.pdfIn PDF document text
    • https://jewfri.kr/files/image/files/34140192950.pdfIn PDF document text
    • http://clubselectionvoyages.com/images/file/99099903619.pdfIn PDF document text
    • https://daquin-ferriere.fr/userfiles/file/wadiwovamexisesidig.pdfIn PDF document text
    • https://www.bevillelecomte.com/ckfinder/userfiles/files/52139307526.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=free+turn+based+rpg+androidPDF 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_off0000fc36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC36 16904 bytes
SHA-256: fdbf89d5768e6a8ef6c32fb8c9f2efcb72d46c5d206f2167663a8b70491eab42
font_01_sfnt_off000127e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127E2 10740 bytes
SHA-256: 3ee187df3b098e4bba86242c8c330f50c66e73d67f2ddc81762d6178246bd0ea
font_02_sfnt_off0001403b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1403B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1