Malicious PDF — malware analysis report

Static analysis result for SHA-256 e4528237f3579161…

MALICIOUS

PDF

76.5 KB Created: 2021-08-21 04:51:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: edcfd519b4f49f4d279840ce9b71fff2 SHA-1: 8708ef461432a002fea69b64cecb145fbe19475e SHA-256: e4528237f3579161bb0f2128fa120ec2da1f61bd203b58073d685680086fc30c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised WordPress sites, suggesting a phishing or malware distribution campaign. The ML classifier and ClamAV detection strongly indicate malicious intent. Although no scripts were explicitly extracted, the nature of the links and the heuristic firings point towards a malicious link farm designed to lure users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://coretry.ru/uplcv?utm_term=how+to+reset+sonar+decoder+without+remote PDF link annotation
    • http://henca.com/files/details/file/66548137806.pdfIn PDF document text
    • http://lmleadmanagement.com/userfiles/files/14748702263.pdfIn PDF document text
    • https://aquariumfargo.com/wp-content/plugins/super-forms/uploads/php/files/2612987bae7b862bc8899217ae9056c2/7305697854.pdfIn PDF document text
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090f9d67ed98---zixepumik.pdfIn PDF document text
    • https://www.pension-chevaux-haras-gabereau.fr/ckfinder/userfiles/files/borinuzenomow.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160dd9429073a1---xakutivubisiverotutitiwo.pdfIn PDF document text
    • https://www.sacda.org/wp-content/plugins/super-forms/uploads/php/files/4gep6p4820a4q0qcljhdq6chr6/livoresojumij.pdfIn PDF document text
    • https://rfcorporation.net/wp-content/plugins/super-forms/uploads/php/files/aa18afc76e74ba761da1866362a06e22/dupekakipuvevog.pdfIn PDF document text
    • https://saam.vn/images/content/file/12773277151.pdfIn PDF document text
    • https://chiuman-hk.com/images/file/6074093227.pdfIn PDF document text
    • http://sooclose.eu/upload/File/20286957793.pdfIn PDF document text
    • https://sip7.pl/autoinstalator/sip7.online/wp-content/plugins/super-forms/uploads/php/files/25024150e5a748ef876696b03a1488bb/soxesuwenafororununo.pdfIn PDF document text
    • https://alkhairi.co.uk/wp-content/plugins/super-forms/uploads/php/files/215ef1ffe670672593a1ecf4505894ad/jijoxuvatiniwosov.pdfIn PDF document text
    • http://xboxheerlen.nl/userfiles/file/86959247164.pdfIn PDF document text
    • https://chupwo.com/editor_upload/file/17476112212.pdfIn PDF document text
    • https://sidexsideaudio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf415fc0d6d---39144642590.pdfIn PDF document text
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/161196904da9dd---31501584660.pdfIn PDF document text
    • https://regeneracion-capilar.com/wp-content/plugins/super-forms/uploads/php/files/2a0b3435bcd476e5fae9175cab38c711/bopitevugepekizazaw.pdfIn PDF document text
    • https://medtek.vn/storage/file/40182685181.pdfIn PDF document text
    • http://abwsalisbury.com/uploads/files/binexokowa.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/aaf5ahr0tnloqjp3qtopp1k5fi/9721039702.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b772f154584---godogagamen.pdfIn PDF document text
    • http://osmed.cz/app/webroot/files/files/64165799193.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_off0000c989.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC989 15976 bytes
SHA-256: 225f9bc837838cf170b661d08f77d6b4ee69971e6f354aae370e65f6a9b3e69c
font_01_sfnt_off0000f290.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF290 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010aa7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AA7 10764 bytes
SHA-256: 44d2e2499fff9de3df061b5bfbe2e7ef3f60a8278bd698a83435c2084f69a1d0