Malicious PDF — malware analysis report

Static analysis result for SHA-256 151f9bf07233dc4f…

MALICIOUS

PDF

88.1 KB Created: 2021-09-05 18:50:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 52de33a8e6cdb5a4caf4314acf4ad973 SHA-1: e7e4dd9520442a0b83528b57b1a38f7c74394ad2 SHA-256: 151f9bf07233dc4f335410ec7685ba291f8b691b9d09bb9898df620c61bc4778
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The presence of embedded URLs and the PDF structure strongly suggest it's used as a lure, likely for phishing or to distribute further malware, aligning with the Spearphishing Attachment technique.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://accessiblevehicleservices.com/userfiles/file/nebifaziwituwev.pdf In PDF document text
    • http://enewind.com/pliki/file/39719267258.pdfIn PDF document text
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/927445746724fe92cedbdfccaa9261b5/japajab.pdfIn PDF document text
    • http://hydrem.ru/images/file/10472929949.pdfIn PDF document text
    • http://intergeored.com/upload/File/zunuxazupagedafuwagivojix.pdfIn PDF document text
    • http://atlantichomeportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608cb087beba2---1347709710.pdfIn PDF document text
    • http://call.ae/wp-content/plugins/formcraft/file-upload/server/content/files/160ac53e115506---45029748030.pdfIn PDF document text
    • http://shqinze.net/admin/upimg/file///73685432576.pdfIn PDF document text
    • http://romanakladatelstvi.cz/userfiles/file/93935460194.pdfIn PDF document text
    • http://progetec.org/userfiles/files/77431206167.pdfIn PDF document text
    • http://antansconstructions.com/ckfinder/userfiles/files/32212361351.pdfIn PDF document text
    • https://www.herewardcarpets.co.uk/wp-content/plugins/super-forms/uploads/php/files/meueh0guq8j7snpscb6f5arfvk/36285790794.pdfIn PDF document text
    • https://slotpt2.com/contents/files/nikojos.pdfIn PDF document text
    • http://middlegeorgiacoinclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075d49f2100e---43162933869.pdfIn PDF document text
    • https://itracmediav5.com/ckfinder/userfiles/files/zokizafonoza.pdfIn PDF document text
    • http://centralcogtc.com/uploads/file/zagaputod.pdfIn PDF document text
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/1607de11fbd95b---gefegurenakulul.pdfIn PDF document text
    • https://roweryelectra.eu/app/webroot/uploads/file/16200883524943.pdfIn PDF document text
    • http://multiseal.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/16124609137538---sadagapunusakikuridiresup.pdfIn PDF document text
    • https://teenvolunteerdallas.org/wp-content/plugins/super-forms/uploads/php/files/2e355fa7552f6a43130a65bdb379d0a3/vejira.pdfIn PDF document text
    • https://tanasiri.com/piceditor/file/vaxapuz.pdfIn PDF document text
    • http://alrabbancapital.com/file/files/zoruritegexakereri.pdfIn PDF document text
    • http://www.mezmat.ru/ckfinder/userfiles/files/lexokaguroxavonovimi.pdfIn PDF document text
    • https://inncredel.com/uploads/36511809815.pdfIn PDF document text
    • https://nstyapi.com/resimler/files/zanobijututitufewuj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=insect+mouthparts+worksheetPDF 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_off0000f43c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF43C 17652 bytes
SHA-256: c004ed2d34a9bf6b54d516ccba4057c96faab20aeca23e1935bcc8666880c036
font_01_sfnt_off00012228.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12228 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013a3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A3F 10728 bytes
SHA-256: bbc188bdb192dacc1b5a6dffdc27a73d87643a0e88b8e62e0b96bc4dc228c250