Malicious PDF — malware analysis report

Static analysis result for SHA-256 79d4826eb16e7f58…

MALICIOUS

PDF

76.0 KB Created: 2021-06-24 15:51:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-27
MD5: d81f3c7a0945af7c606c28dc0b02ca23 SHA-1: fe85f3985cdc3bb0cd0be4c4e884c27a81ffba09 SHA-256: 79d4826eb16e7f580ce90170a34b5a3c54e5b57f4d9aa9035bcd92e01a5be334
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, pointing to numerous URLs, many hosted on compromised CMS uploads or disposable domains. While no scripts were explicitly extracted, the PDF structure and link farm behavior suggest it's designed to redirect users to potentially harmful websites, possibly for phishing or malware distribution.

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://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ba69da33126---27180070720.pdf In PDF document text
    • https://www.crossfitparamaribo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cb5a227471f---57451360668.pdfIn PDF document text
    • http://thicongdiennuocmiennam.com/uploads/files/rakugazolimidinurijuwite.pdfIn PDF document text
    • http://ufnk.fr/app/webroot/files/file/30552335739.pdfIn PDF document text
    • https://xn----8sbaavnccwq4am.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/ef9c3d73f65850d0ff8918db9f293898/38643340805.pdfIn PDF document text
    • https://anpheatingandac.com/nbloom/fckuploads/file/84174275334.pdfIn PDF document text
    • https://www.treehousecare.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606d11ede4bd8---tosuw.pdfIn PDF document text
    • http://builderall.info/userfiles/file/mewopepemizip.pdfIn PDF document text
    • https://medgarlci.com/wp-content/plugins/super-forms/uploads/php/files/9dd1cf8a8ab72bbf18d8a18d200abba6/nosunudilotasesuvezevoxa.pdfIn PDF document text
    • https://amenagementsoleil.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c5bad86f3d---fotijesaripevobosugu.pdfIn PDF document text
    • https://www.etbsupplies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160adc080bc853---kenaborafar.pdfIn PDF document text
    • https://sunwayhk.com/louis/STARKGROUP/ckfinder/userfiles/files/bominajizuvujijuluneruja.pdfIn PDF document text
    • http://livestreaming.group/wp-content/plugins/super-forms/uploads/php/files/j1u0pg0faa70ba2jkbtjk5gs88s1amqv/sefidodewok.pdfIn PDF document text
    • http://sahamit.net/userfiles/file/25610849102.pdfIn PDF document text
    • https://aneri12.cz/res/file/vebetibilawabododewojam.pdfIn PDF document text
    • http://podlahypilat.cz/admin/file/zipemisut.pdfIn PDF document text
    • http://www.segurosfacility.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a879bf98f93---89211633567.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=advanced+grammar+onlinePDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ec23.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC23 5132 bytes
SHA-256: 954c8732fa4fd0dd214c7f685cb8f47d0860187c8bbfba8d875690141e8eb476
font_01_sfnt_off0000fd89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD89 11060 bytes
SHA-256: 6d7df1f3eeb81197ba4c00981db567965ba5bce68153cfe9a7858e291030b491