Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa20cd06803bdb59…

MALICIOUS

PDF

82.5 KB Created: 2021-09-09 18:46:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 286d3928f1c4423bf3dfaf097432ad5d SHA-1: 97861b5a0136e24a1ee4cda9fad2da5268719008 SHA-256: aa20cd06803bdb592c9f518016a123e2cc9d0f008d606de6fbc4a409e0a3c59b
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs, many hosted on compromised CMS upload storage, suggesting an attempt to lure users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The presence of multiple links to PDF files on various domains reinforces the link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://daithanhnam.com/upload/files/zomaxewivutuzit.pdf In PDF document text
    • https://visionbrindes.com/admin/fckeditor/userfiles/file/wuxediru.pdfIn PDF document text
    • http://shrlie.com/upload_fck/file/2021-9-9/20210909033250443220.pdfIn PDF document text
    • http://luchetti.it/userfiles/files/gipibulakedifij.pdfIn PDF document text
    • http://bebelino.ru/userfiles/file/nudikumowamubekatibufub.pdfIn PDF document text
    • http://kamennykoberec.eu/editor_uploads/system/files/70437266026.pdfIn PDF document text
    • https://avigailpekelman.com/sites/default/files/file/sikogilupi.pdfIn PDF document text
    • http://zaintik.org/files/galeria/files/35382338134.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16132623e6c84b---22579095182.pdfIn PDF document text
    • http://geofer.eu/userfiles/files/73380734874.pdfIn PDF document text
    • http://tangneylaw.com/admin/images/file/puvakazebiniduporumafu.pdfIn PDF document text
    • http://xn--e42bt3l.net/upfile/files/bazizabi.pdfIn PDF document text
    • https://dongphuchuytai.com/upload/files/1104894135.pdfIn PDF document text
    • http://conflictfreeelectronics.com/ourprojects/chowki/UserFiles/renuka/file/lufex.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132d10bd6f54---mizefuretevoxipip.pdfIn PDF document text
    • https://cjsc.se/ckfinder/userfiles/files/182101114.pdfIn PDF document text
    • https://nuttydog.hu/ckfinder/userfiles/files/tijoxisasokufapavowupa.pdfIn PDF document text
    • http://puntolinea.org/userfiles/files/46784710273.pdfIn PDF document text
    • http://massiimo.com/piceditor/file/18656715686.pdfIn PDF document text
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1612f191107924---65361217172.pdfIn PDF document text
    • http://wwpokebar.com/uploads/files/sazibokirovu.pdfIn PDF document text
    • https://eyetracking.pl/userfiles/file/40023751910.pdfIn PDF document text
    • http://kidsjeodo.com/images/files/votowanolamuzukupopiki.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=world+war+z+apk+downloadPDF 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_off0000def1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEF1 10124 bytes
SHA-256: 9e481c334f9e76df373f7973531de6b3f5e4aaf2a3db0d8b82b8989017b729c4
font_01_sfnt_off0000f5a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5A8 18108 bytes
SHA-256: c5d9430f993edb6be0fc8852cbdf4ba80e9c5e51bf1d81b0bc18045dc270560e
font_02_sfnt_off0001247d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1247D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1