Malicious PDF — malware analysis report

Static analysis result for SHA-256 a53c42f3c8a4f6c0…

MALICIOUS

PDF

76.8 KB Created: 2021-09-22 21:47:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 924f7508c888d9af1e4d8057c47e402f SHA-1: ca3a567d07ace2de0897253f968e9eb01ff0d0a3 SHA-256: a53c42f3c8a4f6c085006d5c380621877b9bc848baee20aa554f08055bbeef9e
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs, many pointing to compromised CMS upload directories or disposable domains, indicating a link farm designed to redirect users to potentially malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are indicative of a common phishing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://cructi.ru/uplcv?utm_term=best+app+to+watch+web+series+for+free PDF link annotation
    • http://sjccgy.com/userfiles/file/63416377390.pdfIn PDF document text
    • http://geostudio.eu/userfiles/files/32462655939.pdfIn PDF document text
    • https://theipbuzz.com/images/file/ruzajibijawipesevo.pdfIn PDF document text
    • https://oxfordjsr.com/userfiles/file/62375937532.pdfIn PDF document text
    • https://collinite.pl/userfiles/file/18830257856.pdfIn PDF document text
    • http://liburnia.pl/userfiles/file/63690859346.pdfIn PDF document text
    • https://aalatour.com/basefile/b2caalatourcom/files/xisodujunowonomulada.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131ced217ef9---89187438915.pdfIn PDF document text
    • https://deesudcoolingtower.com/userfiles/file/70946400775.pdfIn PDF document text
    • https://augsburger-dartliga.de/uploads/file/67800593201.pdfIn PDF document text
    • http://santabruna.cl/upload/file/71643243292.pdfIn PDF document text
    • http://autofox.lt/ckfinder/userfiles/files/99636080302.pdfIn PDF document text
    • http://msmzizkov.cz/data/dokumenty/sivixebiv.pdfIn PDF document text
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/8a42d786e1a1b1dbc7efd0c9041a6a31/34460146100.pdfIn PDF document text
    • http://140.121.161.111/ckfinder/userfiles/files/87627969362.pdfPDF link annotation
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/16140274675b68---48678873552.pdfIn PDF document text
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/5a276dfe0f027d253f0c557c0ae8f7df/videmokaro.pdfIn PDF document text
    • https://loyalangkorapartment.com/userfiles/file/mejusep.pdfIn PDF document text
    • http://chukysovin.com/img-svc/files/romegibesolagazesuneviges.pdfIn PDF document text
    • http://ayurveda-shiatsu-nice.com/upload/files/86472874778.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_off0000c777.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC777 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000df8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF8E 10708 bytes
SHA-256: 6f297ca57a4fb3b2ce0067ab88e8bcb81880b0d1afc505dc525567a1dcb4454e
font_02_sfnt_off0000f82e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF82E 17592 bytes
SHA-256: a4a2d9664b3e86a5a3ad3c8f10a8b53694033f750143df9717fa2fa06220746b