Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c3798d08ef61a6f…

MALICIOUS

PDF

80.7 KB Created: 2021-09-10 18:43:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 3c685c75d22a93c95ebefa36c846180b SHA-1: 5a481073b812dbd98324466dcfe94aa083dc4cf8 SHA-256: 4c3798d08ef61a6f7ae9a77275fdba87713ce1c2fb89180cbf03709ce67396e4
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to other PDF files hosted on various domains. Heuristics indicate this is a link farm, likely for SEO manipulation or to distribute further malicious content. ClamAV detected this file as Pdf.Phishing.Trojan, and ML classifiers also flagged it as malicious, suggesting it's part of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://bakineshr.az/ckfinder/userfiles/files/ramakefivazojagajet.pdf In PDF document text
    • http://millionsdiscount.com/mo_images/files/65096146035.pdfIn PDF document text
    • http://thehedgerowchronicles.com/ckfinder/userfiles/files/farujilemomikafabe.pdfIn PDF document text
    • https://marjoyunlar.com/calisma2/files/uploads/28850653216.pdfIn PDF document text
    • http://shamayachts.com/upload/file/mexanije.pdfIn PDF document text
    • http://deforma.it/userfiles/files/59435793904.pdfIn PDF document text
    • http://aan.kz/ckfinder/userfiles/files/bekilusofuxika.pdfIn PDF document text
    • http://technimexvn.com/images/ckeditor/files/99918316150.pdfIn PDF document text
    • https://www.zaantraining.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16135192a9a106---lizijib.pdfIn PDF document text
    • https://goodline.by/userfiles/file/tivawubazerim.pdfIn PDF document text
    • http://shengnabei.com/uploadfile/file///2021090415272633.pdfIn PDF document text
    • http://denge.aero/upload/files/17506207639.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613313bea6768---29835238945.pdfIn PDF document text
    • https://bselink.com/userfiles/file/69508851621.pdfIn PDF document text
    • http://swaptoys.org/ckeditor/uploads/files/97055262679.pdfIn PDF document text
    • http://khodahoanglang.com/admin/webroot/upload/image/files/74205734237.pdfIn PDF document text
    • http://idealthailand.com/file_media/file_image/file/baluzikul.pdfIn PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/16135b75132a2b---tanedusaluvunogilo.pdfIn PDF document text
    • http://gu-bo.cn/uploads/files/4354366328.pdfIn PDF document text
    • http://consoles-a-gagner.com/fckeditor/userfiles/file/rixovogig.pdfIn PDF document text
    • http://watthaistuttgart.de/userfiles/file/18277968155.pdfIn PDF document text
    • http://exteractif.fr/pictures/2/makofenedeloxul.pdfIn PDF document text
    • https://zoomkish.com/basefile/zoomkishcom/files/90695952347.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=mamba+gta+5PDF 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_off0000d566.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD566 9956 bytes
SHA-256: 7af0b84591294c7819115a94289e892e28ee157cf47d5d26eccd45b6bba27c7b
font_01_sfnt_off0000eb82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB82 18912 bytes
SHA-256: e0900ba8681ecd87d0f2e92b66d9c124207169d9b931b071697483ed4cf04349
font_02_sfnt_off00011d70.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D70 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1