Malicious PDF — malware analysis report

Static analysis result for SHA-256 88d2cc7dc3446892…

MALICIOUS

PDF

81.6 KB Created: 2021-09-06 08:58:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 5c3cba927750c8dcd42bdb33a271e760 SHA-1: 10fdb453f8340a41fe438b03c9789a27f499e631 SHA-256: 88d2cc7dc34468928f1a88f34fcf4a981a91335fbd33713e8112a6ced134a47d
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external links, many of which point to compromised WordPress sites. The ML classifier strongly indicates maliciousness, and the link farm behavior suggests an attempt to redirect users to potentially malicious content or phishing sites. No scripts were extracted, limiting the analysis of direct execution capabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 5

  • 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://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/7fbb66077366217a6331430cc6145507/6560778219.pdf In PDF document text
    • http://anatolianlgs.com/userfiles/file/91211223259.pdfIn PDF document text
    • https://www.creativetalentnetwork.com/ckfinder/userfiles/files/vukir.pdfIn PDF document text
    • http://manavpublicschool.org/manav/userfiles/file/58955873867.pdfIn PDF document text
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac5f054ddcb---jajibawa.pdfIn PDF document text
    • http://accronline.com/userfiles/file/4758202498.pdfIn PDF document text
    • https://tanthueviet.vn/img_data/files/88195524445.pdfIn PDF document text
    • https://tort-art.ru/userfiles/file/zugibisiramedunebabez.pdfIn PDF document text
    • http://vtaky.sk/media/file/70321713449.pdfIn PDF document text
    • https://doanhnghiepvietnam.org/img_duhoc/files/fajinokibuguligeliz.pdfIn PDF document text
    • http://www.mariabeckmann.com/fotos/uploads/files/85418740822.pdfIn PDF document text
    • https://texigo.tw/upfile/files/2021/07/13/12087106124.pdfIn PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608c9dc6783c8---sepomog.pdfIn PDF document text
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4d6d2f3629---28642618492.pdfIn PDF document text
    • http://joomlacode.org/fckeditor/editor/filemanager/img.php?file=file/ponomurafolesagolefoz.pdfIn PDF document text
    • https://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/160af9d5d58442---lepiwujoxukotuvifiwusi.pdfIn PDF document text
    • http://www.pics4us.de/userfiles/file/mapojorojufore.pdfIn PDF document text
    • https://reviewz.eu/app/webroot/files/userfiles/files/18391202061.pdfIn PDF document text
    • http://mastera-mix.ru/ckfinder/userfiles/files/47148013826.pdfIn PDF document text
    • http://reclameindex.nl/images/uploads/zofulanugurinoloka.pdfIn PDF document text
    • https://www.pfgpartners.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607ef4c37bab9---kazijojifurimoxuzufujuvu.pdfIn PDF document text
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/188ctlnfa43ubfaetn6e10itid/perululaxodob.pdfIn PDF document text
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612621e242037---fukelezo.pdfIn PDF document text
    • http://vivaldiskibus.com/FileData/ckfinder/files/20210825_30F9D76A75BEC4E4.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=reading+books+for+beginners+in+english+pdfPDF 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_off0000d9e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9E5 17704 bytes
SHA-256: b1d17a927f82552fcc217142903f7ab10c276931ba109f1644bd6bda792da71a
font_01_sfnt_off000107ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107BA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011fd1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FD1 10956 bytes
SHA-256: cd5e6e421c15ef78b6baf384bf90d08f846560237daae83e4fc0acf368846ce4