Malicious PDF — malware analysis report

Static analysis result for SHA-256 7c0fa85ea15b4b25…

MALICIOUS

PDF

76.6 KB Created: 2021-09-18 21:49:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e39940ac42c2c3d26853b886d01114a1 SHA-1: 43b02b9f163d766956b9cabb6d3811431ae28ee0 SHA-256: 7c0fa85ea15b4b25336c53704a440dd4cf45064d80b84489d3ae97dae87e9d66
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The document body is heavily obfuscated and unreadable, providing no direct clues to its specific purpose beyond the presence of these URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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 http://fskyok.com/uploadfile/files/navisegulilotodubosivolir.pdf In PDF document text
    • https://etcbt.com/userfiles/file/13095982511.pdfIn PDF document text
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137f37fecada---28261323644.pdfIn PDF document text
    • http://montpellier-businessplan.eu/mbp/upload/images/images/upload/ckfinder/30212713572.pdfIn PDF document text
    • http://wuyioutdoor.com/userfiles/file/8376504987.pdfIn PDF document text
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16131232a28982---92886164186.pdfIn PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/249fvllhrathqcvt15p1dtk4pt/7261513320.pdfIn PDF document text
    • https://www.fangjin.org/ckfinder/userfiles/files/ponenavisupewezit.pdfIn PDF document text
    • http://phamtrangia.com/upload/files/mafiwufaji.pdfIn PDF document text
    • https://smartbrand.ro/mm/file/99715200320.pdfIn PDF document text
    • http://119pump.net/d/files/86656722213.pdfIn PDF document text
    • https://candbco.com/ckfinder/userfiles/files/9197490881.pdfIn PDF document text
    • https://mcq-exambd.com/app/webroot/ckfinder/userfiles/files/fazuxodo.pdfIn PDF document text
    • http://hdurmuslar.com/images_upload/files/terijepakofajib.pdfIn PDF document text
    • http://studioarchoggianiepartners.it/userfiles/files/5481382918.pdfIn PDF document text
    • http://daiduongmetal.com/uploads/ckfinder/files/gapaneludevolo.pdfIn PDF document text
    • https://www.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/dbcb04d7efefd454dd8575e069d77bdf/97778220413.pdfIn PDF document text
    • http://vlajkylevne.cz/UserFiles/File/45175208740.pdfIn PDF document text
    • http://xaydungphongphu.com/uploads/files/biriroresefu.pdfIn PDF document text
    • http://drironcat.com/images/file/99227059110.pdfIn PDF document text
    • https://eslms.com/userfiles/file/lotobex.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=how+to+make+a+video+a+live+wallpaper+androidPDF 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_off0000c8e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8E1 10620 bytes
SHA-256: bb4027f6179942cac9950c9bfe0bdade7a126187dd86e782824c155c6b478c42
font_01_sfnt_off0000e113.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE113 16732 bytes
SHA-256: 8a72d2781990edcfdfd28fdbff2a966f195725b55bf2b120adafc9cc883be0fe
font_02_sfnt_off00010c57.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C57 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1