Malicious PDF — malware analysis report

Static analysis result for SHA-256 664761a4cc332ed0…

MALICIOUS

PDF

79.9 KB Created: 2021-08-29 17:02:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: b38098d5eec31fa468eae251f7306dc6 SHA-1: 379922596a6fbc6bb71ebd13a6517294d5088afc SHA-256: 664761a4cc332ed0c4d7eaaf4e0db2d6e2edfc3f66c022506a8ad2a512106287
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains embedded JavaScript, which is a common technique for executing malicious code within PDF documents. The document also features a link farm pointing to compromised WordPress uploads and disposable hosting, suggesting an attempt to distribute further malicious content or redirect users to phishing sites. The presence of external URIs and the overall structure indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://medvor.ru/uplcv?utm_term=negative+connotation+of+smart PDF link annotation
    • http://centrumbiznesurawicz.pl/userfiles/file/lowamasebifadiwixilol.pdfIn PDF document text
    • http://aberdeeneyes.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160d26d9e513bd---86285735987.pdfIn PDF document text
    • http://eugensa.lt/app/webroot/uploads/userfiles/files/nawex.pdfIn PDF document text
    • http://architettosirocco.it/userfiles/files/zoganemeloz.pdfIn PDF document text
    • http://robalton.es/Albums/images/file///lekaralajikisos.pdfIn PDF document text
    • http://nissanotogovap.com/uploads/images/files/13643846387.pdfIn PDF document text
    • https://vayamcs.com/content_files/files/bemotufa.pdfIn PDF document text
    • http://modnyi-buket.ru/uploads/files/70282028985.pdfIn PDF document text
    • http://www.cenlafilm.com/siteuploads/editorimg/file/lumupeximogikezutekofa.pdfIn PDF document text
    • http://amandatour.ru/js/ckfinder/userfiles/files/gasojine.pdfIn PDF document text
    • https://petikdaun.com/contents//files/viverexagupadur.pdfIn PDF document text
    • https://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/k18iuqbcn0fgauj6tkgnlnaeo9/58902265043.pdfIn PDF document text
    • https://lawina-radom.pl/files/file/jogupawerowokuba.pdfIn PDF document text
    • http://roland-toys.eu/userfiles/file/govebimiduvujeveluf.pdfIn PDF document text
    • https://sckprime.com/wp-content/plugins/super-forms/uploads/php/files/98364ca2554ecb57de599651072055c4/20936049420.pdfIn PDF document text
    • http://tuzy.pl/Upload/file/nituxudo.pdfIn PDF document text
    • http://dbexpertise.fr/catalogue_dynamique/file/33672382984.pdfIn PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097d1d94ebd4---1221510128.pdfIn PDF document text
    • https://floridaholidayplanner.com/wp-content/plugins/super-forms/uploads/php/files/0615b3040ad9e7d38adeafa3b8885531/39517431564.pdfIn PDF document text
    • https://sukienmiennam.com/userupload/files/62631426782.pdfIn PDF document text
    • http://ventilyatsia-v-sochi.ru/ckfinder/userfiles/files/bobubefiravasadixitotige.pdfIn PDF document text
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160bb8d9358990---gazemasolonimotorux.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb093771105---fukonaso.pdfIn PDF document text
    • https://baxsporthorses.nl/userfiles/file/wirujaxekofanegifowumul.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_off0000d3d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3D6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ebed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBED 10676 bytes
SHA-256: da58d1d115253a15dc080ea07bc6126b3b28376023f7fe9f92cb2669a05e3333
font_02_sfnt_off0001046f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1046F 17056 bytes
SHA-256: 02b4c64fd86bbbecead7dbbbc95e0b75b0a23b66f949bffca16c79a59e4c311d