Malicious PDF — malware analysis report

Static analysis result for SHA-256 ec3166ceaf75f2c0…

MALICIOUS

PDF

79.6 KB Created: 2021-09-14 02:28:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 9f662668200bcebff09f5002bb05b27f SHA-1: 7154bc8b5cf562f6c5f8c9471f6b2718995adcf0 SHA-256: ec3166ceaf75f2c05e6f8ca21c5e613c56448d1517adfdc5bb3743a1c26b6509
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm pointing to compromised CMS upload storage and disposable hosting, with numerous embedded URLs. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf, suggesting it's not intended for direct user interaction but rather to host links.

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 https://foodvellythailand.com/upload/files/ketoverufeder.pdf In PDF document text
    • http://sangiorgioautoservizi.com/userfiles/files/44494751163.pdfIn PDF document text
    • http://jeanchapleau.com/userfiles/file/jabuxojapijob.pdfIn PDF document text
    • http://sieuthibongda.net/ckfinder/userfiles/files/senalodor.pdfIn PDF document text
    • https://www.aaptuk.org/ckfinder/userfiles/files/63677029679.pdfIn PDF document text
    • http://kidsjeodo.com/images/files/xedurodasasapalidigefar.pdfIn PDF document text
    • http://video-cycling.de/files/file/zazageja.pdfIn PDF document text
    • http://shanghaicruiseparty.com/uploads/file/sonuneruberavibejok.pdfIn PDF document text
    • https://diphong.com/uploads/nonujoramojufowajileseno.pdfIn PDF document text
    • http://terhautz.com/upload_files/files/714089601.pdfIn PDF document text
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b30b962dc7---88934847516.pdfIn PDF document text
    • http://gelikonline.ru/content/Files/32597519105.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c6c9a02ff6.pdfIn PDF document text
    • http://jobsandhi.com/uploaded_files/userfiles/files/90326637257.pdfIn PDF document text
    • http://medob.org/SITE/files/editor/file/gitifobimix.pdfIn PDF document text
    • http://upoart.com/ckfinder/userfiles/files/26678628838.pdfIn PDF document text
    • http://eegbiofeedback-leszno.pl/userfiles/file/mikosawotil.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139854759d07---65153929906.pdfIn PDF document text
    • http://netisiletisim.com/guvennet/resimlerfiles/73611805076.pdfIn PDF document text
    • https://jin-ji.com/upload/files/futaparirisobozif.pdfIn PDF document text
    • https://ans5680.preneed91.com/upload/files/49098292227.pdfIn PDF document text
    • http://indianspringhomes.net/userfiles/files/xazujizuzeluparop.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ff7f763fd1---35785451250.pdfIn PDF document text
    • http://immobilieninvestors.de/userfiles/file/67602640875.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=best+non+flash+gamesPDF 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_off0000d40b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD40B 17732 bytes
SHA-256: 1941c14e343122304409ea55ba616a988ae4cb22d96a19040147fe8061d841a5
font_01_sfnt_off00010154.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10154 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001196b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1196B 10524 bytes
SHA-256: 2e9092bc48d288f25c91bc94f80ca798417fd62236e7c64d6ff62cdf55e894b0