Malicious PDF — malware analysis report

Static analysis result for SHA-256 da40cf1a6a6161ca…

MALICIOUS

PDF

79.1 KB Created: 2021-10-08 10:46:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: bc90b61f66c0ca75a7ec973371c5b17b SHA-1: 12108b286542227b9f9b2bab3388758766964f2f SHA-256: da40cf1a6a6161ca5c2f98d7bd668d218259ecf79132b5aef7eaaf49c1b04ab8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support its malicious nature. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious document delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://travelworld.ro/userfiles/file/rufitepoxavam.pdf In PDF document text
    • http://testplanet.nl/uploads/files/31364927994.pdfIn PDF document text
    • https://www.cdsale.org.au/application/third_party/ckfinder/userfiles/files/34481298290.pdfIn PDF document text
    • http://www.prctech-th.com/ckfinder/userfiles/files/jabuwokivoxigimisojumo.pdfIn PDF document text
    • https://insolite.lu/img/userfiles/files/titexaxabekepe.pdfIn PDF document text
    • http://ovartec.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b748bd7a85---zetuvigubigipasoludurixa.pdfIn PDF document text
    • https://ebus.myskoolapp.com/FCKeditor/FCKimgUpload/file/sabibesudumatawigiveje.pdfIn PDF document text
    • http://mn-print.ru/ckfinder/userfiles/files/vokamotogez.pdfIn PDF document text
    • http://automsystem.com/UploadFile/file/20210918025330124.pdfIn PDF document text
    • http://goraku-sangyo.com/userfiles/file/tifixudusin.pdfIn PDF document text
    • http://movitecnic.com/ressource/site-image/files/32829975961.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/38ncnetpvq3d6l70rsv71vkmoc/45050340221.pdfIn PDF document text
    • https://kurek-rowery.pl/user_pict/file/tarusuvakugojoninaxono.pdfIn PDF document text
    • http://alwaysshine.com/fileimage/file/jidalulifivugotisibogen.pdfIn PDF document text
    • http://beijingteye.com/upload/files/kozemarukadefofijutivi.pdfIn PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/56b63gqfu09rp78romtato530d/meromunovukukuludaxuweto.pdfIn PDF document text
    • http://kerama.altrodesign.eu/ckfinder/userfiles/files/dusowomixoda.pdfIn PDF document text
    • https://happycondo.leaddeehub.com/userfiles/files/43983727816.pdfIn PDF document text
    • https://floridainvestment.cz/files/file/5315528202.pdfIn PDF document text
    • http://zhihepvb.com/upload/ckimg/files/202109041001133571.pdfIn PDF document text
    • http://thriftstorewebsites.com/flash/thriftstorewebsites.com/file/podanuxamimivizilidunopu.pdfIn PDF document text
    • http://nepalbestcargo.com/userfiles/file/ratirojoxojupo.pdfIn PDF document text
    • http://gr-chem.com/upload/files/12955340818.pdfIn PDF document text
    • http://logisticsnetworks.net/ckfinder/userfiles/files/fewalelogeref.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=places+to+visit+in+mauritiusPDF 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_off0000cf32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF32 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e749.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE749 10560 bytes
SHA-256: 60408b0aa0b736b08bc16c20d44d38dd4d7733892cea922bb4edc6ef5730b069
font_02_sfnt_off0000ff5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF5C 18516 bytes
SHA-256: ae300f31276c954b2fe3c2c9e35ad6c5da7bbfa319f33e0fb80165dc0548ad13