Malicious PDF — malware analysis report

Static analysis result for SHA-256 50a4771f4eb01f56…

MALICIOUS

PDF

78.0 KB Created: 2021-09-13 19:05:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: b86be3a0077e50a00af6d9cdcd489d4d SHA-1: 943afc6f47d29b65559e69cf4957fb2f5d57b508 SHA-256: 50a4771f4eb01f569f1f42c1e1766a2d66568f7655a5cd87c1db6d58e1ef6703
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external URIs and is described as a link farm hosted on disposable or compromised domains, suggesting a phishing or malware distribution lure. Although no scripts were explicitly extracted, the PDF structure and embedded URLs point towards an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://nomylo.ru/uplcv?utm_term=rheo+tv+apk+download+for+android PDF link annotation
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136aef7089d0---xitegakodopajavud.pdfIn PDF document text
    • http://rowadhr.com/app/webroot/upload/files/domifejasased.pdfIn PDF document text
    • http://paitoonbox.com/userfiles/files/zabozepixivetewuvamunox.pdfIn PDF document text
    • https://zohopin.com/calisma2/files/uploads/namivibajikir.pdfIn PDF document text
    • http://sensi-leszno.pl/userfiles/file/fuxoduwenunuzanil.pdfIn PDF document text
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/161310bdb8ffae---rolepi.pdfIn PDF document text
    • https://mmoxx.mn/userfiles/files/51527747011.pdfIn PDF document text
    • https://studiecarriere.it/uploads/file/80337846607.pdfIn PDF document text
    • http://xn--80aab8aioy.xn--p1ai/userfiles/file/90922847237.pdfIn PDF document text
    • https://cezartravel.hu/userfiles/file/87305517861.pdfIn PDF document text
    • https://cissud.com/uploads/ck_editor/files/57585293879.pdfIn PDF document text
    • http://erainbowrealty.com/userfiles/file/39142203203.pdfIn PDF document text
    • https://www.sevgiliyevideo.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613b7ecd9d6ae---pagirowolibadugev.pdfIn PDF document text
    • http://www.sospapa24.com/lib/ckfinder/imgupload/files/vadikemavij.pdfIn PDF document text
    • https://wilocom.ro/ckfinder/userfiles/files/raxewadegagogofugalaj.pdfIn PDF document text
    • http://lamekatus.com/uploads/ckeditor/files/2670744368.pdfIn PDF document text
    • http://heathrowairporttaxi.website/userfiles/file/dokoxa.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/wesed.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/bawuveripenunu.pdfIn PDF document text
    • https://myclubowners.com/userfiles/files/pajejawowe.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_off0000cb37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB37 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e34e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE34E 10716 bytes
SHA-256: d85b8d79a94a6821b79fa379a29d0a041cbe62c89ddaac4ab8473abaf94f57a6
font_02_sfnt_off0000fbe1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBE1 18324 bytes
SHA-256: 1944905da67f1cef51dae98d35fa27a68db182366024c6ef2731d6e5161a9460