Malicious PDF — malware analysis report

Static analysis result for SHA-256 31f5abe968fb43e2…

MALICIOUS

PDF

84.7 KB Created: 2021-09-12 13:07:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 75a5ce6ab4b4388b72584f5c0448da00 SHA-1: 1e2df589220fa6cd5bd16f4b9f3b212ea4b25ac8 SHA-256: 31f5abe968fb43e21abbee79a7b885cd6bf72f5cfb8cf45cff10a7ec45d759a7
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to other PDF files hosted on disposable or low-reputation domains, indicating a link farm or redirection scheme. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://sbmhavacilik.com/userfiles/file/5083249044.pdf In PDF document text
    • http://mojahotels.com/ckfinder/userfiles/files/69955416450.pdfIn PDF document text
    • http://ctmmaximoravenna.com/ckfinder/userfiles/files/81809475917.pdfIn PDF document text
    • http://dolphinkorea.com/files/files/98017357010.pdfIn PDF document text
    • http://studiomedicoveterinariobellucci.eu/userfiles/files/74612042901.pdfIn PDF document text
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137ab7633050---melumugila.pdfIn PDF document text
    • https://rtvpuls.com/ckfinder/userfiles/files/8310271443.pdfIn PDF document text
    • http://irodaszer.lukinserv.hu/file/zekepumuj.pdfIn PDF document text
    • http://www.synagoge-stommeln.de/ckfinder/userfiles/files/xowexugodorisitupaxawax.pdfIn PDF document text
    • http://bacsiha.com/public/ckfinder/userfiles/files/galakuxewetu.pdfIn PDF document text
    • http://yuhao-tech.com/userfiles/file/bakedobolilepudijede.pdfIn PDF document text
    • http://soundspace.eu/Upload/file/72145508461.pdfIn PDF document text
    • http://uniondrygoods.com/fckeditor/userfiles/file/rujipejirogut.pdfIn PDF document text
    • http://perlawarmii.pl/userfiles/file/bebepiravukiroguvaje.pdfIn PDF document text
    • http://thehedgerowchronicles.com/ckfinder/userfiles/files/vuvanudag.pdfIn PDF document text
    • http://kbfrutos.sk/images/_file/kokafobazokivatesapazinuz.pdfIn PDF document text
    • http://xn--80adpfaaeictf0c6c7i.xn--p1ai/public/file/jenavolapagog.pdfIn PDF document text
    • https://plagij.at/ckfinder/userfiles/files/fapitupimibowejobelufu.pdfIn PDF document text
    • https://dpt-mh.com/uploads/news/files/46852478080.pdfIn PDF document text
    • http://estatepie.com/files/userfiles/file/93172472395.pdfIn PDF document text
    • https://kclandscapes.com/ckfinder/triplebuserfiles/file/woderifidex.pdfIn PDF document text
    • http://unitez.net/images/newtech/files/11973889612.pdfIn PDF document text
    • http://theclubburger.com/uploads/files/vudot.pdfIn PDF document text
    • http://www.web-globus.de/ckfinder/userfiles/files/gabowegokajupiromu.pdfIn PDF document text
    • https://ivanamihic.com/files/nokimedunefub.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=parallax+app+for+androidPDF 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_off0000e78e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE78E 10196 bytes
SHA-256: 6b706733e43c824c00b5930d5825adcdc105e83e6a094073d4f70cf01c2db8e9
font_01_sfnt_off0000fe63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE63 18056 bytes
SHA-256: bb765e34f4c2a8a8431fe9b166b985a383a9e62fc25b5e2f41e85075a665b0fa
font_02_sfnt_off00012d51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D51 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1