Malicious PDF — malware analysis report

Static analysis result for SHA-256 c08bff3f1e6638ce…

MALICIOUS

PDF

91.2 KB Created: 2021-08-18 17:50:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 27654c1f92d326e9ad00b2e31a8952a4 SHA-1: e2dc4e50b57b842f24b2daea6694a3eccce7e266 SHA-256: c08bff3f1e6638ce085fef9a999a2b84fd7698dbb749d6c50c0ee1c018e32383
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file is identified as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm. It contains numerous URLs pointing to compromised WordPress sites, which in turn host other PDF files. This suggests an attempt to manipulate search engine rankings or distribute further malicious content. No scripts were extracted, and the document body was unreadable, limiting the analysis of specific payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9913

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 https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160e48703a99b2---39644958180.pdf In PDF document text
    • http://grupomarsamo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d55a686a57---kulikalikovemobojaxunonoz.pdfIn PDF document text
    • http://xn----gtbercbfedtm3b.xn--p1ai/admin/ckfinder/userfiles/files/88440255123.pdfIn PDF document text
    • https://medtek.vn/storage/file/bakiwebogonisek.pdfIn PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160abad2bd1a0a---87429395824.pdfIn PDF document text
    • https://erinmillssmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/a12rk0i5v351ep36hl6tvi7jk6/robubugajupapilafegane.pdfIn PDF document text
    • https://www.ideaklinik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16093e6ef3b666---dikevilufijinuzatod.pdfIn PDF document text
    • http://etkindenetim.com/resimler/files/872008969.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160ee76a6aed7e---56550426493.pdfIn PDF document text
    • https://photojet.net/userfiles/file/musunawe.pdfIn PDF document text
    • http://modnyi-buket.ru/uploads/files/gonumasuvefebodejar.pdfIn PDF document text
    • https://tarzminder.com/resimler/files/kikezaf.pdfIn PDF document text
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608768e11fb2d---88780407485.pdfIn PDF document text
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/285efa533cc32605836727c49230618c/wetimaxo.pdfIn PDF document text
    • http://gourmethousemacau.com/UploadFilesfile///76060004267.pdfIn PDF document text
    • https://thetitangroup.ca/wp-content/plugins/super-forms/uploads/php/files/897796b6d04f1ab617bd7d958253ffc9/silogipafidugafivewaga.pdfIn PDF document text
    • http://terapeutickemasaze.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1607e86cb896db---16807422900.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/hsgnudb7i4h0148ijp8qti5thq/voponunufodijexeru.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160e85c8450908---88681128201.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/hc09qbn9ggvv2h17barle80sv1/wezitimemigirepi.pdfIn PDF document text
    • http://lysfyyy.com/upload/files/fibudul.pdfIn PDF document text
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d7324b02f2---39517890640.pdfIn PDF document text
    • https://xo-sound.ru/userfiles/file/fugarugofuwafa.pdfIn PDF document text
    • https://beaufortbond.com/wp-content/plugins/super-forms/uploads/php/files/3149e4110a1dfb409ccf16082929d723/7528895013.pdfIn PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/82e32a040b0b93ccfd4b2b3c9c8e92ab/mofezepilaj.pdfIn PDF document text
    • https://spa-salon.ru/ckfinder/userfiles/files/92241509965.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=genie+garage+door+opener+keypad+resetPDF 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_off000101f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101F5 10768 bytes
SHA-256: 50c1e83fd0ebe0a963da160731354333307439d2657908391016b0981e78cbd6
font_01_sfnt_off00011ab8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AB8 16824 bytes
SHA-256: 38b33876ddc3b8b864f67fdcaddb512232430b6abf82140a836777c32e9d6f9d
font_02_sfnt_off000146a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x146A5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1