Malicious PDF — malware analysis report

Static analysis result for SHA-256 f91373ffad4a6a81…

MALICIOUS

PDF

85.2 KB Created: 2021-09-12 16:36:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 44182684464bdb730c831a96e22de719 SHA-1: d689d3e5c61e8e0fbb25dc93d08ae8a9dd8f151d SHA-256: f91373ffad4a6a811325439451c01929c188ab214b7647f9d34607e540c2e083
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a ML classifier and ClamAV, indicating it is likely a phishing or malware distribution lure. The presence of numerous embedded URLs, many pointing to compromised or disposable hosting, supports the attack pattern of a link farm designed to redirect users to malicious content. The ClamAV detection name 'Pdf.Phishing.Trojan' further reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 https://www.luthier-auxerre.fr/ckfinder/userfiles/files/bifetiviwiw.pdf In PDF document text
    • https://proartgaleria.hu/files/files/28995825704.pdfIn PDF document text
    • https://www.benkorner.nl/admin/library/ckfinder/userfiles/files/29508778867.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/vigupubupoperaputimutekat.pdfIn PDF document text
    • https://aukshanya.promosing.com/alpha/ckfinder/userfiles/files/73018223675.pdfIn PDF document text
    • http://vyveva.eu/UserFiles/File/56244160056.pdfIn PDF document text
    • http://zatoodesign.com/userfiles/files/toledotiviredirisikanikit.pdfIn PDF document text
    • http://sinice-rasy.cz/files/file/54070630959.pdfIn PDF document text
    • http://fmi.lu/userfiles/files/rifaluguwijuwa.pdfIn PDF document text
    • http://grupomarsamo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161359f2845c3f---jabebebizopubiwelekafo.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c02a347dcb---gafawomarafomevalos.pdfIn PDF document text
    • http://chornakorn-packing.com/ckfinder/userfiles/files/batoniju.pdfIn PDF document text
    • http://kossuthdigisuli.hu/userfiles/file/mozep.pdfIn PDF document text
    • http://studiomalpocher.it/userfiles/files/1418564073.pdfIn PDF document text
    • https://sergiomauri.com/images/file/zibijazo.pdfIn PDF document text
    • http://lumieretvie.com/userfiles/file/95439046471.pdfIn PDF document text
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/311c768a308d2b144dd4f1539a3ebc11/15071977569.pdfIn PDF document text
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16136048d5c140---4022193751.pdfIn PDF document text
    • http://ljjxmining.com/uploadfile/file///2021090809253972.pdfIn PDF document text
    • https://www.sensiblemachines.com/ckfinder/core/connector/php/files/nuxan.pdfIn PDF document text
    • http://cuacuonbinhduong.com/upload/files/xedulafatonidedadames.pdfIn PDF document text
    • http://xn----7sbab1bcaqplb0ccyi9d.xn--p1ai/files/file/pirafukimipu.pdfIn PDF document text
    • https://jyapa.com/jhuoyue/uploadfiles/wekagekoseximunopes.pdfIn PDF document text
    • http://ziconiavip.com/uploadfck/file/89382140802.pdfIn PDF document text
    • https://ppkh.net/userfiles/file/68872607717.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=news+of+the+world+putlockerPDF 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_off0000e694.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE694 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000feab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEAB 10612 bytes
SHA-256: fca72aab6eaf5c2f22fa32291515ed998407389a83e4bd5e9f47de76e4e9f4bf
font_02_sfnt_off00011731.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11731 18888 bytes
SHA-256: 5235ffff4c99789400f092ede8c1f97e92bcb3b33cfb6faa945c48a4d70f14ad