Malicious PDF — malware analysis report

Static analysis result for SHA-256 f33575e8a6740ca0…

MALICIOUS

PDF

99.9 KB Created: 2021-08-12 16:50:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6a19017649eede3fc8b63e0c9b150fdc SHA-1: a3dbd2cc25be1e582671c860b71d2db42596f913 SHA-256: f33575e8a6740ca03db37e31eea3cafbe0c01dd118037c9c6927df91adcf9df8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of embedded URLs, many of which point to compromised CMS upload directories or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. Although no scripts were directly extracted, the structure suggests it functions as a link farm, a common tactic for initial access via spearphishing attachments.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

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://directorvincentchow.com/fck_filemanager_upload/file/27530528686.pdf
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608170d5269de---94946289128.pdf
    • http://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/513779f7ae7261d26b4373e530788383/bivegavikew.pdf
    • http://dmhu.eu/uploads/uplib/file/60719716271.pdf
    • http://classicalgardenfountains.com/uplds/file/83832947544.pdf
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/16070dc02ce3cd---68873428532.pdf
    • http://vizugy.hu/uploads/files/bividiximozaxunitaboxop.pdf
    • http://homespakistan.net/magzine/uploadfiles/file/4548434232.pdf
    • http://contextuae.com/resimler/files/13836450729.pdf
    • https://thietbidienmanhcuong.com/upload/files/vogazupigoziv.pdf
    • http://bestforfishing.com/wp-content/plugins/super-forms/uploads/php/files/8403a294ccc04ab64e50652f838b3903/33035230140.pdf
    • https://samavetpharm.com/userfiles/files/raxivesujovi.pdf
    • https://grnca.org/img/files/files/86422959448.pdf
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/0qsgs0he8m5v6jr2mm2s3alus4/rubewikefaxi.pdf
    • http://lev-steklo.ru/userfiles/file/vereriririgobasut.pdf
    • http://dietmoiquangle.com/webroot/img/files/91040965230.pdf
    • https://scavilecis.it/userfiles/file/sukawejekokuvef.pdf
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/1609289d5db549---88719869255.pdf
    • http://anhuifan.com/upload_fck/file/2021-6-26/20210626170939532731.pdf
    • http://angarakshaksecurity.com/userfiles/file/51068396916.pdf
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/e2dj2jkj4nvbd4ook85p0q0guq/24307850619.pdf
    • http://ssujaxchapter.com/clients/83257/File/dudijo.pdf
    • http://zdrowejaja.com/Upload/file/woxefanefefigevu.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=getting+started+with+aws+machine+learning+coursera+quiz+answers+github
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011c9e.bin
af42a95f208054ffc86c4660a4aa20eb456768c48d9c2b880ac3d8b6ae3b8a95
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C9E 18732 bytes
font_01_sfnt_off00014e71.bin
031818251bffe25dea5b90968a8b61a0803d3ed04632ca695123ef782bf43e6f
pdf-font-stream PDF embedded font (sfnt) at offset 0x14E71 11388 bytes
font_02_sfnt_off000168b8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x168B8 16792 bytes