Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb5b97cb426d0aed…

MALICIOUS

PDF

86.3 KB Created: 2021-09-12 21:25:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: ba9d1498f8cc15946f4f10ba85c0b11d SHA-1: bf988bf0a985fbf0d46688e1ab213997e25980c5 SHA-256: cb5b97cb426d0aed395e9d48df2e0d99053d62aa245542d990b142f1410869c0
156 Risk Score

Malware Insights

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

The file is a PDF containing numerous links, many of which point to compromised WordPress sites and disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution. While no scripts were extracted, the structure and URL patterns are consistent with attempts to exploit users via malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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 https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fc8101b5f9---74141651235.pdf In PDF document text
    • http://eko-baby.ru/userfiles/file/63467982510.pdfIn PDF document text
    • http://hengfengpaper.com/filespath/files/20210908031915.pdfIn PDF document text
    • http://lrpharmaceutical.com/upload/files/ronezeviranokibesi.pdfIn PDF document text
    • http://ana-jsc.com/upload/files/380164802.pdfIn PDF document text
    • https://www.singaporemedicalclinic.com/ckfinder/userfiles/files/90094108292.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/16138c1ed5f401---vupujebabigurekexu.pdfIn PDF document text
    • https://tese.in/ckfinder/userfiles/files/dopetodavoz.pdfIn PDF document text
    • http://mitcostruttori.it/userfiles/files/97071690219.pdfIn PDF document text
    • http://mopron.ru/upload/files/gupuvuma.pdfIn PDF document text
    • https://urology-andrology.com/userfiles/file/kamakuzexalet.pdfIn PDF document text
    • http://musicandyouapp.com/webupload/editorimg/files/sojigamowotarejebeduluw.pdfIn PDF document text
    • http://turatabor.hu/media/68896025278.pdfIn PDF document text
    • http://findmecakes.com/userfiles/files/depalejudaxagepuboze.pdfIn PDF document text
    • https://dellrein.ru/content/file/pasefenuxijijukojawarod.pdfIn PDF document text
    • https://hmjrgoldhockey.org/wp-content/plugins/super-forms/uploads/php/files/fb6adb0fe913b36aff439f1cb982accd/46649934976.pdfIn PDF document text
    • https://www.crossfitparamaribo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135e7e3dca48---xenexitatubonagimijivo.pdfIn PDF document text
    • http://peneleos.pl/userfiles/file/15842627468.pdfIn PDF document text
    • http://kindergartenhelden.at/upload/file/pusosewe.pdfIn PDF document text
    • http://strahovka66.ru/userfiles/file/puwosovewomit.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=transfer+music+files+from+pc+to+android+phonePDF 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_off0000eb4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB4B 10948 bytes
SHA-256: ec33e0dc5e4c00f63b56df038b4d4bff60b1e5152a4150f66cd272d1ecb8235f
font_01_sfnt_off0001046e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1046E 18112 bytes
SHA-256: 307af6f98c030c8d80320de9ada4e26f616f043f62e7e57ebc8e1546a0ac88b1
font_02_sfnt_off0001334e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1334E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1