Malicious PDF — malware analysis report

Static analysis result for SHA-256 91a131d84e4ffd70…

MALICIOUS

PDF

83.3 KB Created: 2021-09-15 18:45:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 668bf8aa4617b310408619ec71a1f441 SHA-1: 4270ea437fa713092c150c383fc538c1e277d65d SHA-256: 91a131d84e4ffd7064d1ca62243cfbf317cb2f3ca9e4f90d047b778d7abe1b12
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to potentially compromised or disposable hosting, suggesting a link farm or phishing lure. The PDF structure and embedded content are consistent with attempts to redirect users to external malicious sites, likely for further exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://drairtools.com/ckfinder/userfiles/files/rarovivoxademozajafudab.pdf In PDF document text
    • https://incense888.com/uploads/files/202109020456269370.pdfIn PDF document text
    • http://sonhanint.com/uploadpic/sun/files/202109040053013145.pdfIn PDF document text
    • http://rasciindia.com/firetech/ckupload/files/gafomelizopalopamexebafa.pdfIn PDF document text
    • https://gbp.dropship-online.com/userfiles/files/92107873029.pdfIn PDF document text
    • http://isleford.com/filespath/files/20210915172827.pdfIn PDF document text
    • http://jadever.vn/Images_upload/files/mejut.pdfIn PDF document text
    • http://gimnazjum-krasiczyn.pl/img/userfiles/file/26562744759.pdfIn PDF document text
    • http://global-gypsum.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ef16ae711d---wovigisumupixeminukeput.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132079911303---43810254471.pdfIn PDF document text
    • https://produktybhp.pl/pliki_user/File/duruwipurovinuseb.pdfIn PDF document text
    • https://apoiotelecom.com/imagens/img_fckeditor/file/wedojixariloridemopimir.pdfIn PDF document text
    • http://sampoernastrategic.com/uploads/image/files/42766463308.pdfIn PDF document text
    • http://faradtvandor.hu/picture/userfiles/file/pajanabijanumejizoku.pdfIn PDF document text
    • http://orthodoxvaidikasanghom.org/userfiles/file/rapuzidanul.pdfIn PDF document text
    • http://boston.pl/fck_pliki/file/30695638816.pdfIn PDF document text
    • https://washlounge.in/ckfinder/userfiles/files/67892873263.pdfIn PDF document text
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/1613bffc70bc1b---44776900655.pdfIn PDF document text
    • https://thefencedocumentary.com/adminfiles/file/resulujagepubuv.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161310724f3021---30751057512.pdfIn PDF document text
    • https://radekslodkiewicz.pl/files/file/91323770018.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=qualitative+research+and+case+study+applications+in+education+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_off0000e101.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE101 17152 bytes
SHA-256: d73d9f31a43e8c9ad0129264eb25ef9fd5d6b461ff01337e30c61df2f9392b89
font_01_sfnt_off00010d45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D45 11056 bytes
SHA-256: 8c675cc5b4fc1cc20b04a7c63f7601d3d1b5f86b47458caef83b9a719ac71840
font_02_sfnt_off00012716.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12716 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1