Malicious PDF — malware analysis report

Static analysis result for SHA-256 99e9c9929d70511a…

MALICIOUS

PDF

81.2 KB Created: 2021-09-17 15:06:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 841e4a902e54a130ac5a9d97a881e0c8 SHA-1: b72f026fa11eea4a4a54225119686206d439e1b9 SHA-256: 99e9c9929d70511adeb7d9320c5827806539be805a9f52ccd7ec98d14d16f661
156 Risk Score

Malware Insights

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

The PDF file contains a large number of links, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://bighost.vn/uploads/userfiles/file/59955377527.pdf In PDF document text
    • http://31kouqiang.com/userfiles/file/1631297988.pdfIn PDF document text
    • http://gsemilia.it/userfiles/files/63074518334.pdfIn PDF document text
    • https://dom4m.de/userfiles/files/99558960912.pdfIn PDF document text
    • https://implant-drill.com/userfiles/file/12816371072.pdfIn PDF document text
    • http://phukiendoxe.com/media/ftp/file/75104291905.pdfIn PDF document text
    • http://chrisnoblelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/ruxoporusopoxotetafakem.pdfIn PDF document text
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/1613f17f9def77---dedafunuloxoduwavupagoj.pdfIn PDF document text
    • http://caopump.com/admin/userfiles/file/68731681598.pdfIn PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/1614061e26bbcf---savuvixodivafujelotu.pdfIn PDF document text
    • https://njshore.drinkpoint.com/uploads/files/95588177151.pdfIn PDF document text
    • http://xn--22cjbbm2eyae3ehabdb4kqdtae3dxnnc1fhf.com/user_img/files/97467546759.pdfIn PDF document text
    • http://nasfthr.com/userfiles/file/jusovejijevokoxilikato.pdfIn PDF document text
    • http://netichikawaya.com/userfiles/file/5164958842.pdfIn PDF document text
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16138b1532a6a0---20828968789.pdfIn PDF document text
    • https://segurosjdd.com/wp-content/plugins/super-forms/uploads/php/files/9qq97ngoopt537291u1ql97a14/76223961767.pdfIn PDF document text
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c90e2c9af6---32943209454.pdfIn PDF document text
    • http://enovosti.info/ckfinder/userfiles/files/4960042205.pdfIn PDF document text
    • http://uniquecharacters.com/upload/files/48050092354.pdfIn PDF document text
    • http://recko.ru/ckfinder/userfiles/files/bipeguxijira.pdfIn PDF document text
    • http://ttworld.hu/uploads/content_files/files/50832218131.pdfIn PDF document text
    • https://stiff.pl/ckfinder/userfiles/files/puvurisolesisum.pdfIn PDF document text
    • http://yoshitomo-kokubunji.com/jcfiles/file/wuwarutagawajotuluz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=android+camera+ocrPDF 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_off0000da66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA66 17452 bytes
SHA-256: 0eed5e1a6c6f5755aeaa5d78c2227da29ea8b158708f796c22ddd68a4abeec22
font_01_sfnt_off00010846.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10846 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001205d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1205D 10200 bytes
SHA-256: dc2a1591cfe469d99bddee4ae96cb44a110fcb0f9d5275fabd3df79ff2d757ab