Malicious PDF — malware analysis report

Static analysis result for SHA-256 d28374dd8157f283…

MALICIOUS

PDF

69.9 KB Created: 2021-09-18 15:20:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 6c717d07d6924d2e9676abee05dd6e00 SHA-1: 8113346b082b20069c662f3f1563d19b47ba42d7 SHA-256: d28374dd8157f28382b4a0d17e449d74eea5e13515306dd6339a089e9a9b8ade
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to domains flagged as compromised or disposable, suggesting a link farm designed to distribute malicious content or phish users. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://teamtrinity.net/trinitya/file/zewup.pdf In PDF document text
    • https://renebeumer.nl/userfiles/file/xurewot.pdfIn PDF document text
    • https://jimsdelibrookhaven.com/demo/jimsdeli/admin/userfilesfile/dolukuvimodilibureralemum.pdfIn PDF document text
    • http://sostrevalli.it/userfiles/files/54938508134.pdfIn PDF document text
    • http://zulaikhatextile.com/userfiles/files/63764690475.pdfIn PDF document text
    • https://bjjewels.net/nbloom/fckuploads/file/79377506536.pdfIn PDF document text
    • https://biocoils.com/img/file/7613809804.pdfIn PDF document text
    • http://delannahotel.com/user_img/file/27719578337.pdfIn PDF document text
    • http://stimatacasa.eu/userfiles/files/xagobijavofazejutixivote.pdfIn PDF document text
    • https://heyratacademy.ir/file/retubuxixiberagat.pdfIn PDF document text
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/b9ea511b0f3791e2f82efef743c4619d/17801520401.pdfIn PDF document text
    • https://iringmalaysia.com/ckfinder/userfiles/files/paronawizifawuvi.pdfIn PDF document text
    • https://adikketiga.com/contents/files/44624645803.pdfIn PDF document text
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/16144d95b1c731---xufujo.pdfIn PDF document text
    • http://yanartekstil.com/firma/files/fewedu.pdfIn PDF document text
    • https://dichvuketoanvn.org/uploads/files/71398927951.pdfIn PDF document text
    • http://fueandhair.com/userfiles/files/rawinijojibi.pdfIn PDF document text
    • http://kapalishakti.com/ckfinder/userfiles/files/35718023058.pdfIn PDF document text
    • http://ahknchem.com/upload/files/51365287152.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132406336027---makulafonasej.pdfIn PDF document text
    • http://velocimapper.com/webfiles/file/nowiderikatexubolili.pdfIn PDF document text
    • https://tese.in/ckfinder/userfiles/files/geketixofitovomatidav.pdfIn PDF document text
    • https://escaletravel.com/userfiles/files/64346138286.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=flutter+build+unsigned+apkPDF 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_off0000b362.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB362 10756 bytes
SHA-256: 70b3cbe0b373226038bf04bcb33df5875c268913f08c19cdce487f2d33fb8d39
font_01_sfnt_off0000cbc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBC3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e3d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3D5 15388 bytes
SHA-256: 1a18409838c82a1459f60f514de318e8f944ea6d5ada08431e5ebe9d08ac4417