Malicious PDF — malware analysis report

Static analysis result for SHA-256 db5c6256f6b214f6…

MALICIOUS

PDF

80.7 KB Created: 2021-09-10 13:36:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: b415643c66821fbfee583e0912f64e1f SHA-1: 5716dcc4d4b54690f9d8417cb1537a25c11416a6 SHA-256: db5c6256f6b214f65158efffb56f686155888d3dff0156d44b69756605bc5215
156 Risk Score

Malware Insights

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

The file was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS uploads. The PDF's structure and embedded links suggest an attempt to redirect users to potentially malicious sites for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://akproauto.com/nbloom/fckuploads/file/kigakukasemakamusezag.pdf In PDF document text
    • http://caudafotografia.com/userfiles/files/34107523946.pdfIn PDF document text
    • http://www.malagatour.es/ckfinder/userfiles/files/pebuxovirob.pdfIn PDF document text
    • https://sport-jicin.cz/dokumenty/93855733630.pdfIn PDF document text
    • http://spy-military-labs.com/userfiles/file/97618678467.pdfIn PDF document text
    • http://joyear.com/ckfinder/userfiles/files/wizibuganetojofeziruda.pdfIn PDF document text
    • https://pasarantogel.com/contents/files/90497264824.pdfIn PDF document text
    • http://fobosgrunt.ru/files/ckfinder/files/73404426537.pdfIn PDF document text
    • https://osikovo.eu/webroot/img/content/files/15292036349.pdfIn PDF document text
    • https://cheesykeju.com/contents/files/29876580648.pdfIn PDF document text
    • http://www.drivingschool-brno.cz/files/files/87687763490.pdfIn PDF document text
    • https://www.intermediastudios.com.mx/wp-content/plugins/super-forms/uploads/php/files/7aa7a99d8d8e897304da99392fcffc4a/55345340597.pdfIn PDF document text
    • http://el-master.ru/userfiles/file/rebujudude.pdfIn PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612eb82bac3b5---gujetemuwimi.pdfIn PDF document text
    • https://ubranni.com/uploader/files/gawitorisajana.pdfIn PDF document text
    • http://karpatskiles.ru/store/files/80274576095.pdfIn PDF document text
    • http://sakaryakasaplarodasi.org/userfiles/file/noniwegijarigogazese.pdfIn PDF document text
    • http://brcassociati.com/userfiles/files/70788330367.pdfIn PDF document text
    • http://hsaltsj.com/uploads/files/41367791801.pdfIn PDF document text
    • http://123podkrovie.sk/editor_uploads/files/81760066835.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1612f14b5ee689---jubugulerepepanazafetuw.pdfIn PDF document text
    • https://drlalashow.com/php/billboard/uploads/file/52615435381.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=chrome+in+android+tvPDF 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_off0000d85a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD85A 10396 bytes
SHA-256: 847c1ddde523ac8ccb8fa13e60f7748cbfa5ed8b1dc82641cbc373a5c148cc0b
font_01_sfnt_off0000efb8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFB8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000107ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107CA 17660 bytes
SHA-256: 2ff4fae909d085294512829ec6ebff1dc174470cca7dcc270abfb348a32bcc9e