Malicious PDF — malware analysis report

Static analysis result for SHA-256 d41fa0ec139077b4…

MALICIOUS

PDF

98.9 KB Created: 2021-09-14 10:29:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: f8a1ca1c85fd8fd9145ff37ab4ced35f SHA-1: 295850fa2d88fbb99392150a6c1d4e531a3447fd SHA-256: d41fa0ec139077b4245835857d10e4bd1a3d1096f8d2056cac4b15bf3eef65e2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://tubemakingmachine.com/uploadfile/files/86845015986.pdf In PDF document text
    • https://medpressa.ru/files/file/71891932741.pdfIn PDF document text
    • http://hugslock.com/app/webroot/img/files/kewafudanudofumejikamuk.pdfIn PDF document text
    • http://mousike.it/img_ins/files/gujopelelojo.pdfIn PDF document text
    • http://szyuangang.com/UserFiles/file///62677737651.pdfIn PDF document text
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16131a4be165d9---29982255416.pdfIn PDF document text
    • https://codecs.ro/images/file/xuxijoduxemetejogujamow.pdfIn PDF document text
    • http://ghettaetamionarchitetti.it/userfiles/files/57287826740.pdfIn PDF document text
    • http://3wsystems.com/shipinc/userfiles/files/85910853841.pdfIn PDF document text
    • http://sbkf.org/files/files/rilalikoka.pdfIn PDF document text
    • http://instalace-charvat.cz/userfiles/file/jikisumiko.pdfIn PDF document text
    • https://minhvuongthuphap.com/upload/ck/files/6174390084.pdfIn PDF document text
    • https://playerpress.com/ckfinder/userfiles/files/29899462075.pdfIn PDF document text
    • http://hantechwelding.com/userfiles/file/2021090821252273499.pdfIn PDF document text
    • https://towa-aaa.jp/userfiles/file/73989736356.pdfIn PDF document text
    • http://www.valathors.com/ckfinder/userfiles/files/16938337511.pdfIn PDF document text
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b3eb9b2de2---11498018581.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/161339b3535994---dorevavuzoku.pdfIn PDF document text
    • https://nhatngudongkinh.phapluatvietnam.com/upload/ckupload/files/wozabokilisitededabuzaki.pdfIn PDF document text
    • https://abriganature.centralcms.cloud/galeria/files/natejezidironarovoduze.pdfIn PDF document text
    • https://dcoderesearch.com/uploads/zokitigejutanod.pdfIn PDF document text
    • https://rcvizovice.cz/ckfinder/userfiles/files/safokogugisajavufibezan.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=tides+of+war+apkPDF 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_off00011b8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B8D 19832 bytes
SHA-256: 80faa37f100134e25d987bb7c1c99426e59c9b350408060bb886b5fcf6680329
font_01_sfnt_off00014ef1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14EF1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00016708.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16708 10384 bytes
SHA-256: 7023870e75931ca1de713577629b13725ed81d2eee86b37847e7e59ebc7d9933