Malicious PDF — malware analysis report

Static analysis result for SHA-256 c741621a9310e0f1…

MALICIOUS

PDF

77.9 KB Created: 2021-09-09 09:47:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 7b25114ae4af46db331a4bbaa7228060 SHA-1: 7ebe52a57e040c62b131fd971c49b8d9067a519b SHA-256: c741621a9310e0f1aed5083fb96e5902ea8014c6db6814868df3f56b3af34d0b
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, with a high heuristic score for being a link farm on disposable hosting. The PDF contains 31 embedded URLs, many of which are structured with UTM parameters, indicating a likely phishing or traffic-driving campaign. While no scripts were explicitly extracted, the nature of the embedded links and the heuristic firings strongly suggest an attempt to lure users to external, potentially malicious, sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://cructi.ru/uplcv?utm_term=android+pokemon+go+hack+2020 PDF link annotation
    • http://hcwan.com/userfiles/file/93534807642.pdfIn PDF document text
    • http://shtaket46.ru/page_edit/_samples/userfiles/files/80452355896.pdfIn PDF document text
    • http://insightonafrica.in/userfiles/file/nurixigevivaler.pdfIn PDF document text
    • http://qfse.co/images/uploaded_files/ckfinder/files/1630611891_3cf0fdf61d.pdfIn PDF document text
    • http://effektfilm.de/files/file/lepibuleraladematafibuxel.pdfIn PDF document text
    • https://hocaukhudothithanhphogiaoluu.com/asset/site/files/widakafatinimunokav.pdfIn PDF document text
    • http://mariekevanvlierden.nl/survey/userfiles/files/pisataguparub.pdfIn PDF document text
    • https://mitrasuksesku.com/userfiles/file/33231418726.pdfIn PDF document text
    • http://somsit.com/ckfinder/userfiles/files/74826451195.pdfIn PDF document text
    • https://szaniterplaza.hu/ckfinder/userfiles/files/42046593072.pdfIn PDF document text
    • http://www.sm.ac.th/ckfinder/userfiles/files/nabefaropafojuv.pdfIn PDF document text
    • https://www.tristar-technology.com/ckfinder/userfiles/files/82752385490.pdfIn PDF document text
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133982f49095---10275788290.pdfIn PDF document text
    • https://horkolas-gatlas.hu/ufiles/file/2920114627.pdfIn PDF document text
    • https://abisspaandboutique.com/nbloom/fckuploads/file/76177620356.pdfIn PDF document text
    • http://realfootball.gr/userfiles/file/nozobimixeleza.pdfIn PDF document text
    • https://tanthueviet.vn/img_data/files/veludisoli.pdfIn PDF document text
    • https://ms2gacor.com/contents/files/xinugeninolojiv.pdfIn PDF document text
    • https://pelicanfinancialnetwork.com/ckfinder/userfiles/files/97766059744.pdfIn PDF document text
    • https://epagneuls-bretons.fr/caningest/images/file/pikepobov.pdfIn PDF document text
    • http://ecohost.ru/pics/images/file/giripupow.pdfIn PDF document text
    • https://dbhattacharjee.com/ckfinder/userfiles/files/49951768370.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_off0000c878.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC878 10964 bytes
SHA-256: 9e1f47cc39b1ace019bf05cd03cbf597b6af1c7be9f4e28984a3ffd603998c16
font_01_sfnt_off0000e183.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE183 18280 bytes
SHA-256: 571761e2ae127d17a54468dba79ad9229856748349d1b4f1ed5500101fd8b88b
font_02_sfnt_off00011094.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11094 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1