Malicious PDF — malware analysis report

Static analysis result for SHA-256 e4487cf5bf0640dc…

MALICIOUS

PDF

88.3 KB Created: 2021-06-18 04:50:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-15
MD5: 39e80395a75a32e378918cc7327f9890 SHA-1: 1288c039e59c61d45e7dad992af14c6f0ce7278b SHA-256: e4487cf5bf0640dc1534ac6547732276a907600ed3e645049fe62ab0c34ebb7e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous embedded URLs pointing to compromised WordPress sites, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of a malicious document, potentially leveraging embedded JavaScript for redirection or further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://www.varisistanbul.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b8f7f08fb7---nopisujugasewilibo.pdf In PDF document text
    • http://akinmedical.com/uploads/file/vusorifuzexojavevilupu.pdfIn PDF document text
    • https://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1609014fa54a04---46667204851.pdfIn PDF document text
    • https://www.zulilighting.com/wp-content/plugins/super-forms/uploads/php/files/fa2aa37917ab542a16176bcd03f64434/zifugex.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/f9k5p75oga6a1p8qgva22oc320/91072931003.pdfIn PDF document text
    • https://webtraffic.ch/wp-content/plugins/super-forms/uploads/php/files/uidce1t9i31li5hl8e9crg7jjk/40483500832.pdfIn PDF document text
    • http://xn--80aamdqpfpr.xn--p1ai/upload_picture/11234483045.pdfIn PDF document text
    • http://anhbanglaw.com/userfiles/file/40895889281.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1609f1bda1f97c---jenugibaxoneruri.pdfIn PDF document text
    • http://vilaportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af5d12f211f---siwikukax.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf9bc764615---10868343923.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1fa90f1c3e---jadamuvetegewawapiwelupum.pdfIn PDF document text
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160aa59a46cecd---bumujotagamedimoja.pdfIn PDF document text
    • https://www.demetagras.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ce3cd346e4---webubirakolimip.pdfIn PDF document text
    • http://adaviestransportltd.com/userfiles/file/68900493057.pdfIn PDF document text
    • https://infravoip.com/wp-content/plugins/super-forms/uploads/php/files/d912e57d9d24ccf2ac60e1a662560861/janumodomibo.pdfIn PDF document text
    • http://dzwigipoznan.pl/userfiles/file/51735534808.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=futile+devices+piano+sheetPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011f07.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F07 5080 bytes
SHA-256: 57e3f35058068b563b92a9b55bd10fa23e11bcd989a5546c67d8a630cc9d7a5b
font_01_sfnt_off00013057.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13057 12136 bytes
SHA-256: db7304ac604d6e5006cdc75159ea85925cb90a97a7f37ebf3b4fb8fe29332840