Malicious PDF — malware analysis report

Static analysis result for SHA-256 335b4003e08a8cd5…

MALICIOUS

PDF

74.2 KB Created: 2021-09-07 16:04:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 04e75ce19452350163c4222f923d71b0 SHA-1: b4f2e37a44053678e0e724e9e81a01f06cd48b05 SHA-256: 335b4003e08a8cd5799a5a08af009771f5374d8a3154cb8db6ebb05cfd4690a8
176 Risk Score

Malware Insights

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

The sample is a PDF document identified as malicious by ClamAV and an ML classifier. It contains numerous external URIs, many pointing to compromised CMS upload storage or disposable hosting, suggesting it functions as a link farm. These links likely lead to phishing pages or further malware downloads, aligning with a spearphishing attachment attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://synerhu.ru/uplcv?utm_term=processador+triturador+manual+de+alimentos+3+l%C3%A2minas PDF link annotation
    • http://ppfi-online.com/userfiles/file/50034169867.pdfIn PDF document text
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a6bcce1b6bb---kagob.pdfIn PDF document text
    • http://rulife.ru/ckfinder/userfiles/files/nagasofetegeva.pdfIn PDF document text
    • https://holocaustresearch.pl/nowy/photo/file/bujafaxegogonuzubu.pdfIn PDF document text
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/160780f51a1a22---83736412618.pdfIn PDF document text
    • http://www.perchegouet.com/ckfinder/userfiles/files/39296644558.pdfIn PDF document text
    • http://ghinelliarchitettura.it/userfiles/files/38270348011.pdfIn PDF document text
    • http://www.lightingandhvacexpo.com/wp-content/plugins/super-forms/uploads/php/files/5a5955c7ee3bdbfa6c098159cf4f33e3/dovijisuw.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609bd35ab20ca---20721850150.pdfIn PDF document text
    • http://mobil-tech.com/files/nibapoboxabogobodu.pdfIn PDF document text
    • http://kahasat.cz/data/file/xolifopagofavevutelida.pdfIn PDF document text
    • https://mihalex.by/files/files/gidoxuvodunod.pdfIn PDF document text
    • https://autonoleggioassereto.com/file/32452064617.pdfIn PDF document text
    • http://alibabashipping.com/userfiles/file/joragabesojuwunasav.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/4473b27e9298972144782f60478cb646/53874837267.pdfIn PDF document text
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608228792f27d---12736881698.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/a81ec3ee6944797afa7a9cc15db23104/jifemunaginuxolukusori.pdfIn PDF document text
    • http://headlinesdinerla.com/uploads/files/morakulol.pdfIn PDF document text
    • http://www.kindytennis.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4338820cb6---luseluxugotazupolapiwokir.pdfIn PDF document text
    • http://dobrasekacka.cz/userfiles/file/lopeto.pdfIn PDF document text
    • http://elonsummerstorage.com/wp-content/plugins/formcraft/file-upload/server/content/files/160972ff89a6b1---japawise.pdfIn PDF document text
    • http://proreferee.ru/uploads/ckfinder/files/dezifosudesajarekan.pdfIn PDF document text
    • https://easternresources.net/ckfinder/userfiles/files/83929905425.pdfIn PDF document text
    • http://areawifi.com/DESARROLLO/userfiles/files/47371876765.pdfIn PDF document text
    • http://140.121.125.49/ckfinder/userfiles/files/20210715_173538.pdfPDF link annotation
    • https://militarynetwork.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16071998424dc3---gerigebufupobiwutateze.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_off0000ba48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA48 18184 bytes
SHA-256: fa39bfeab642fc58e1fc61a53138a09d834950298cfa9d748a49a0f16cf91c32
font_01_sfnt_off0000e6fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6FD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ff14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF14 10992 bytes
SHA-256: e04a4b58b8d20bcba6694872cb075b648a21f778e19f1f962ea33f6b2dd45132