Malicious PDF — malware analysis report

Static analysis result for SHA-256 6b4abb34c0f3a101…

MALICIOUS

PDF

80.9 KB Created: 2021-09-20 19:07:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 28efe13cc88a794729fa2db991e1111b SHA-1: 33d119daf2714f96693ca884e72f1697f0ccf6e0 SHA-256: 6b4abb34c0f3a10145ec2e9651581bcf10a5d4e4be9b07cc22b1d4ffd99dc9de
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious Link

The PDF file contains numerous embedded URLs that point to various domains, many of which are associated with compromised content management systems or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of a link farm suggests an attempt to obscure the ultimate destination and potentially evade detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://smidgel.ru/uplcv?utm_term=free+fire+game+download+new PDF link annotation
    • http://pol2-simf.ru/userfiles/file/28792168254.pdfIn PDF document text
    • http://modaxch.com/userfiles/files/73458224339.pdfIn PDF document text
    • http://zaun-produzent.de/userfiles/file/rokevusimagedetifodaxed.pdfIn PDF document text
    • https://www.asoriofrio.org/ckfinder/userfiles/files/rigaka.pdfIn PDF document text
    • http://rklatex.com/userfiles/file/71591509173.pdfIn PDF document text
    • https://istanajp.com/contents/files/49832543828.pdfIn PDF document text
    • http://csc-vietnam.vn/uploads/userfiles/file/kotosakolabizumafovavuxet.pdfIn PDF document text
    • http://safarang.com/basefile/files/wotaboza.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1613486b0d19fe---lofonunabijoto.pdfIn PDF document text
    • https://wentworthre.com/wp-content/plugins/super-forms/uploads/php/files/8baf6086f61dcdfa13e8a86915ac683e/vaxapafudujizo.pdfIn PDF document text
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/3an6qs3th5mo4lsjjp4ga5go2m/33093018087.pdfIn PDF document text
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/161467b72333dd---susunirajozemejetiwi.pdfIn PDF document text
    • https://pepinieramontana.ro/ckfinder/userfiles/files/jejejoxofafudexinokuv.pdfIn PDF document text
    • https://safewatersolutions.in/ckfinder/userfiles/files/pukisupixutaber.pdfIn PDF document text
    • https://ilexgold.com/app/webroot/files/userfiles/files/popigovuroremufexurobikow.pdfIn PDF document text
    • http://visit-pune.com/userfiles/file/vovikerozazajigufu.pdfIn PDF document text
    • http://xn--80aer5aza.xn---42-5cdakyymnnb9ake1az.xn--p1ai/ckfinder/userfiles/files/vabazudowimepi.pdfIn PDF document text
    • http://baoveantam.org/upload/files/rudijup.pdfIn PDF document text
    • http://busangh.com/attfile/fckimg/file///2021091695233_319846415.pdfIn PDF document text
    • https://thehouseproduction.net/file/xarinawifa.pdfIn PDF document text
    • https://pelicanfinancialnetwork.net/ckfinder/userfiles/files/14070083565.pdfIn PDF document text
    • http://mastervin.ru/files/file/88638392774.pdfIn PDF document text
    • https://www.havanasalsa-dance-tours.com/wp-content/plugins/super-forms/uploads/php/files/cb907fc48c2dba19c4cc1a8cd8b017ec/maduv.pdfIn PDF document text
    • http://ildong.org/sa_upload/userfiles/file/20210908232303.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_off0000d800.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD800 17756 bytes
SHA-256: 7e68e98cd0a13d9d8c31843d8a411c2e0f8f56d283400d664d7a98042dc98717
font_01_sfnt_off00010657.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10657 10492 bytes
SHA-256: b69ef4dbea0a1c93012ba513a42b21a6a632e5b6d0bf83b3f0844aea44554b8c
font_02_sfnt_off00011df4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DF4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1