Malicious PDF — malware analysis report

Static analysis result for SHA-256 707a8941b350bba0…

MALICIOUS

PDF

80.6 KB Created: 2021-09-14 11:19:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: d21eee84fa399c2479bf7f8a879766cc SHA-1: 37c28ea18f25ffa9408204bc4410a63f98c4a59f SHA-256: 707a8941b350bba04ec250f90a16d9c12c34bb2c0c3de6b3d5f04980973db1ad
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF contains a link farm pointing to multiple compromised websites, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of embedded URLs and the structure of the PDF, which appears to be generated by wkhtmltopdf, are consistent with techniques used to host malicious content and redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://laborke.ru/uplcv?utm_term=android+app+development+on+mobile PDF link annotation
    • http://abwhopewell.com/uploads/files/dafademezomevekor.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161304f189f136---zututese.pdfIn PDF document text
    • https://archcosmeticstudio.com.au/wp-content/plugins/super-forms/uploads/php/files/0508034232aed40817dd410b1ebdfd7d/7177241569.pdfIn PDF document text
    • http://liveranigioielli.it/userfiles/files/gazivekulunodelegupemeva.pdfIn PDF document text
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/8ifa12geglpoia8dl32i6igc81/dimekeni.pdfIn PDF document text
    • http://thibidi.vinadesign.info/uploads/images/files/biwedutaza.pdfIn PDF document text
    • https://tskrea.com/userfiles/file/waxag.pdfIn PDF document text
    • http://mayinmaunhat.com/upload/files/kegokirevupoxewobapexoz.pdfIn PDF document text
    • https://www.theknowledgeonline.com/files/lib/ckfinder/userfiles/files/86641997509.pdfIn PDF document text
    • http://bushurov.ru/images/files/nefojolasevibezow.pdfIn PDF document text
    • https://doublehair.center/upload/ckfinder/files/kobofevozabovavivibon.pdfIn PDF document text
    • http://xaydungphongphu.com/uploads/files/dixafadudafozanixaza.pdfIn PDF document text
    • http://lyzph.com/userfiles/file/Fl202109122147111075.pdfIn PDF document text
    • http://ximangsongthao.com/app/webroot/uploads/files/ximerug.pdfIn PDF document text
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/16138fc8a262d4---wegijedinelizos.pdfIn PDF document text
    • http://ambvet-trefontane.eu/userfiles/files/90938101010.pdfIn PDF document text
    • https://shreenatharcade.com/userfiles/file/23895386906.pdfIn PDF document text
    • http://xn--aknmedcal-wpbe.com/uploads/file/74614096454.pdfIn PDF document text
    • http://thietkewebbacninh.com/webroot/img/files/wowoze.pdfIn PDF document text
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1612fea0c30fc2---7677772361.pdfIn PDF document text
    • http://madmojo.com/fckupload/file/xulatalafuxizuliwutel.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_off0000d636.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD636 18048 bytes
SHA-256: 483fdc248683274b502041c4be78573e2ee0390682f1a9d589fe959dfcb8fb6a
font_01_sfnt_off00010530.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10530 10572 bytes
SHA-256: 8a87a0e7f521d3d8e120b0f202b0427369f2c24e8721590f60bee8a5d1d98dc6
font_02_sfnt_off00011d07.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D07 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1