Malicious PDF — malware analysis report

Static analysis result for SHA-256 a13a80cac1febbe8…

MALICIOUS

PDF

84.1 KB Created: 2021-09-15 14:46:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 63ea95caaba735bfc4d144e46dac8d1e SHA-1: 208b419912d0569d22f4d21748999a98a73d9e30 SHA-256: a13a80cac1febbe8aa3a05e278e7ab0c594cf8a88e1e3b4329bf738bf6ed7802
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs and is flagged by ClamAV and an ML classifier as malicious, specifically as a phishing trojan. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of hosting many links on disposable domains, suggesting a phishing or spam campaign. While no scripts were explicitly extracted, the presence of external links and the nature of the heuristics strongly suggest the PDF is intended to redirect users to malicious websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://ketchas.ru/uplcv?utm_term=alight+motion+mod+apk+download PDF link annotation
    • http://nanopena.cz/upload/file/29151644997.pdfIn PDF document text
    • http://www.c-l-r-p.com/admin/ckfinder/userfiles/files/vamoluj.pdfIn PDF document text
    • https://basalyemek.com/ckfinder/userfiles/files/87644101556.pdfIn PDF document text
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/16140cbf23cf1f---10228773577.pdfIn PDF document text
    • http://ydtmuhendislik.com/ckfinder/userfiles/files/gaxikuduta.pdfIn PDF document text
    • https://www.serwkom.pl/plugins/ckfinder/userfiles/files/4272812303.pdfIn PDF document text
    • http://maility.pl/_ADRESuserfiles/file/94287952931.pdfIn PDF document text
    • https://www.allduniv.ac.in/ckfinder/userfiles/files/9213959612.pdfIn PDF document text
    • http://15881588.com/ckupload/files/zibex.pdfIn PDF document text
    • http://skpizzasubs.com/uploads/files/ralet.pdfIn PDF document text
    • http://skncn.com/u/files/8378943346.pdfIn PDF document text
    • https://novamakine.com/upload/ckfinder/files/nilamedifopu.pdfIn PDF document text
    • http://psychologkmalinowska.pl/ckfinder/userfiles/files/jolatemumumabu.pdfIn PDF document text
    • https://biomedchita.ru/imeg_master/file/numevije.pdfIn PDF document text
    • http://aasghsflqsae.handylover.com/upload/files/83787077516.pdfIn PDF document text
    • https://dalycity.com/wysiwygfiles/file/89332297066.pdfIn PDF document text
    • https://pisangmanis.com/contents/files/69352865131.pdfIn PDF document text
    • http://easternhoteljeju.com/FileData/ckfinder/files/20210910_5614DD83356B6478.pdfIn PDF document text
    • http://csc020.com/userfiles/file/20210910222051_h3jn73.pdfIn PDF document text
    • https://turbooto.vn/upload/files/xibinosekoxa.pdfIn PDF document text
    • http://luisacortesearchitetto.it/userfiles/files/fuzitovalaw.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_off0000e501.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE501 17740 bytes
SHA-256: c27f41521f8cc572aeafc592afe935f836d0568f98bc822c882e8511426fa124
font_01_sfnt_off000112c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112C8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012adf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12ADF 10600 bytes
SHA-256: 76ffb293957bcddbcc355a9525007b1f0c5dd3322c98f9a1ce163b32d3660dab