Malicious PDF — malware analysis report

Static analysis result for SHA-256 aec1a89ca840d785…

MALICIOUS

PDF

81.5 KB Created: 2021-09-17 04:33:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 89395c97782d58d4a049b0b987b3dab4 SHA-1: 640bafddb54951d0fb0c443c8b8da1313aa43e20 SHA-256: aec1a89ca840d7856dd448c0bf4694a8e9eb810c7d4f49539d5ebb42a59a2577
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, indicative of a link farm used for phishing or malware distribution. The ClamAV detection and ML classifier strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious document delivery, likely via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://smidgel.ru/uplcv?utm_term=arthr+root+word PDF link annotation
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16140f7b3d2590---66949303629.pdfIn PDF document text
    • https://europawindow.com/app/webroot/img/main_content/files/78781234014.pdfIn PDF document text
    • http://leguido.net/files/12394483518.pdfIn PDF document text
    • https://charlesstreetvideo.com/userfiles/file/rifepefotomow.pdfIn PDF document text
    • http://pasted-radio.de/web/files/14358653078.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/1613bcc3ba04c0---54652407867.pdfIn PDF document text
    • https://collinite.pl/userfiles/file/sezusaluxum.pdfIn PDF document text
    • http://becucci.it/userfiles/files/9562573246.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161342fa03437c---14077412472.pdfIn PDF document text
    • https://7mark3t2-7aya.com/contents/files/78099594498.pdfIn PDF document text
    • http://centromedicoveterinarioadda.com/userfiles/files/kilozisevigupuje.pdfIn PDF document text
    • http://msinziniering.com/userfiles/file/96640024787.pdfIn PDF document text
    • http://tlxzkj.com/uploads/file/100555535522.pdfIn PDF document text
    • http://jshanwoo.com/ckfinder/userfiles/files/68640971073.pdfIn PDF document text
    • http://burragebrothers.org/demo/jolie/beta/userfiles/files/70293179917.pdfIn PDF document text
    • http://www.scea.edu.mn/ckfinder/userfiles/files/13759493591.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613e2904516ac---kinezagufisu.pdfIn PDF document text
    • http://klenderbio.com/upload/files/lanatarajefuzoxuro.pdfIn PDF document text
    • https://srmhomes.com/images/bulk_images/files/wosev.pdfIn PDF document text
    • http://saltokisport.com/uploads/files/49792848160.pdfIn PDF document text
    • http://nemochem.cn/upload/files/naxodepopapopi.pdfIn PDF document text
    • http://santeh.md/img/files/bikav.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_off0000d39c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD39C 21664 bytes
SHA-256: ba2bccbaacfe0a4cdc5b36d04b111bde0f43333ab0fc17d0f75b2f4960c8fee0
font_01_sfnt_off00010b5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B5A 9708 bytes
SHA-256: 26b52fc3cddc24cde51f34e72e202b4f02704c78ee9f5967838f8d1e948bb5e9
font_02_sfnt_off000120b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120B0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1