Malicious PDF — malware analysis report

Static analysis result for SHA-256 4815053cfdf506e2…

MALICIOUS

PDF

74.5 KB Created: 2021-09-09 01:45:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 08a7e51884879a7008d4ee9a875f9505 SHA-1: 64a6d870ff65157b426847bfbfd2c4e18248b420 SHA-256: 4815053cfdf506e2a41d81b90f2bb3e67e5c52add537777869e8733c46fa5874
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document flagged by ClamAV as Pdf.Phishing.Trojan. It contains embedded JavaScript and a significant number of external URIs, many of which point to disposable hosting or compromised CMS uploads, indicating a link farm designed to redirect users. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://chatsystem.site/js/ckfinder/userfiles/files/73817009553.pdf In PDF document text
    • https://karapinarinsaat.net/userfiles/upload/file/rudokunadajefeg.pdfIn PDF document text
    • https://www.kiemtoandongnghi.com/public/plugins/ckfinder/userfiles/files/sozepulabujebutezez.pdfIn PDF document text
    • http://arkystudio.eu/userfiles/files/62152129443.pdfIn PDF document text
    • http://zhjpharm.com/upload/files/28416012391.pdfIn PDF document text
    • https://charterboatdeliverance.com/uploads/files/66890633163.pdfIn PDF document text
    • https://contemporaryteas.in/admin/uploads/file/jelikubaxix.pdfIn PDF document text
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/8a517131151fda8a69aaf8652cbde271/dubujiluxekozuxisavuxi.pdfIn PDF document text
    • https://rubin2000-distribuitorshop.ro/userfiles/file/worerap.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/rosabasos.pdfIn PDF document text
    • https://avukat.dnsaktif.net/upload/files/sokekaborekekeza.pdfIn PDF document text
    • https://tekartltd.com/upload/files/82933155854.pdfIn PDF document text
    • https://x-leather.com/radsportfiles/file/33770104298.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/diwaxodepowosaz.pdfIn PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/15q2jdj6tfq943fmrtdjhpcdhb/guxuzofelabilim.pdfIn PDF document text
    • http://shriadinathbank.com/uploads/9817828613.pdfIn PDF document text
    • http://phamtrangia.com/upload/files/bagewi.pdfIn PDF document text
    • http://didopack.com/files/maxuvixoxex.pdfIn PDF document text
    • https://tjp2-hotlink-j3t.com/contents/files/suparajemolizevebiv.pdfIn PDF document text
    • https://congchungnguyenlieu.vnpec.xyz/uploads/files/55382769529.pdfIn PDF document text
    • https://www.blackandwhite-salon.com/wp-content/plugins/super-forms/uploads/php/files/tmp/7180787276.pdfIn PDF document text
    • http://npk-bypassdrr2.com/file_media/file_image/file/93122718599.pdfIn PDF document text
    • http://duancanhotot.com/upload/files/56967566777.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=punjabi+ttf+fonts+free+download+for+androidPDF 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_off0000bd11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD11 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d528.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD528 10804 bytes
SHA-256: 984d45d516f61bb328ae88c86f1bc8217d9640baea0af0ec5d168e6f564b28cd
font_02_sfnt_off0000ee30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE30 17128 bytes
SHA-256: 26978666043f43294f872003600412ab5252eed522782bd42aac911abbc65deb