Malicious PDF — malware analysis report

Static analysis result for SHA-256 810823158b1c3411…

MALICIOUS

PDF

88.1 KB Created: 2021-10-05 12:26:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: b7747067671e9ccf20c4f317990a9ea2 SHA-1: 85eea4a09e75e6733487aa2834e24345d763556b SHA-256: 810823158b1c34113364e39fdb532fb45735845a5d226f70996aa691d8c177fd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to potentially compromised CMS upload directories or disposable hosting. While no scripts were extracted, the PDF structure and numerous external links suggest an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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 http://chetaomaynganhnhua.com/uploads/files/70646693847.pdf In PDF document text
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1614077f7483bc---guwagunir.pdfIn PDF document text
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/161390e699fc25---vupejixe.pdfIn PDF document text
    • https://cpsguffanti.com/uploads/file/liribudopij.pdfIn PDF document text
    • http://youngthisyear.com/ckfinder/userfiles/files/47114835333.pdfIn PDF document text
    • http://3gr-group.com/ci/userfiles/files/3872623905.pdfIn PDF document text
    • http://heizler.hu/files/file/11707824421.pdfIn PDF document text
    • http://webinaris.net/ckfinder/userfiles/publics/files/zisezi.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/1615b30025f31d---17374935170.pdfIn PDF document text
    • http://maimungkorn.com/UserFiles/file/12280508471.pdfIn PDF document text
    • http://cz-synergy.cz/data/file/48709148850.pdfIn PDF document text
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/1614577ac695ed---24996847655.pdfIn PDF document text
    • http://nensi.si/upload/file/faletogemadubalekofivo.pdfIn PDF document text
    • http://offerseir.com/basefile/offerseircom/files/nekewokaxat.pdfIn PDF document text
    • http://sevvalturizm.com/rsm/files/rureretutuwixotuxoweli.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/161347c8f2f90c---puranoritewibulusexuni.pdfIn PDF document text
    • https://dursunguney.com/userfiles/files/92783797778.pdfIn PDF document text
    • https://asztromiskolc.hu/ckfinder/userfiles/files/98048764818.pdfIn PDF document text
    • http://baozhaopharma.com/upload/files/55199133782.pdfIn PDF document text
    • http://studioarchterreni.it/userfiles/files/68247083390.pdfIn PDF document text
    • https://soudurelauziere.ca/upload/editor/file/jarinojesaxonegufugowoj.pdfIn PDF document text
    • http://ghemassagenhatban.vn/Images_upload/files/buwakurajejujibekan.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=postprandial+hyperglycemia+meaningPDF 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_off0000f180.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF180 18780 bytes
SHA-256: 768a8b427b2b6e22ae91c9549ecb32790a3dff88159a9a5e98b0b48724ef8726
font_01_sfnt_off0001212e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1212E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013945.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13945 11076 bytes
SHA-256: ad1d823173ca9e89eecb0d27329adc6c4f08f52280fbb91a5b1acfc06008bd38