Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ff0d5aa8eff50cd…

MALICIOUS

PDF

93.1 KB Created: 2021-06-16 09:55:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: b0a8a8145573a9d25bb43b5a0632e4c8 SHA-1: 5c329fd92c6fa543ab2a5b9366752a2af98e73f2 SHA-256: 4ff0d5aa8eff50cd3b6d4c7a05788f5543658909c64fe8e4bc433230cfc758df
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous external URIs and links to compromised CMS upload storage, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the embedded URLs are the primary indicators of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://synerhu.ru/uplcv?utm_term=surah+al+mulk+pdf+alkalam+pk PDF link annotation
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/0f57f15a8cc041f96add1ebff0fea7fa/7896658813.pdfIn PDF document text
    • https://www.keystonecare.co.uk/wp-content/plugins/super-forms/uploads/php/files/dacb67972f77da158cec6190968a6c3a/jukagaxe.pdfIn PDF document text
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/160748ce143edb---tixeratimu.pdfIn PDF document text
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ab49d0920d---54446990313.pdfIn PDF document text
    • http://tuzvedo.hu/elemek/file/mojopojizozokinonofegif.pdfIn PDF document text
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160ace3c7ec19d---dupuvazisedokepoberevuba.pdfIn PDF document text
    • https://666666.vn/upload/fck/file/4649932770.pdfIn PDF document text
    • http://villaturri.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a68ab6c6125---funewiteri.pdfIn PDF document text
    • https://xn--80aaaglcftt5alesfkk7f.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/9eb7802585c008b3960e1b112e114cbc/71137740312.pdfIn PDF document text
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/ebc478bb8e24664d6f7adabc6c24cd8c/10428145296.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/bdi7bl9ha75a8fpu2pkjmuh211/81443973457.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/1606cde0bc349f---6533577481.pdfIn PDF document text
    • http://schooldistrictservices.com/clients/f/f6/f6ab1571d2cdf5e569af7b76e288b17c/File/40789874883.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off000146bc.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x146BC 19744 bytes
SHA-256: b39cb4814094618922d73dca7d58fc8f9f816e54f3e7c70930cafea2691ba57e
font_00_sfnt_off00010b9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B9A 5268 bytes
SHA-256: 21ac38126f3979567d8448e7bc4c4132cf53c8d8ee6b1b138deb3283a4475c72
font_01_sfnt_off00011d58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D58 12792 bytes
SHA-256: 0ac5d94a3b37a58c209bdc6a5a2d4f101476b959bdc6ef49f8013ffd76c02e19