Malicious PDF — malware analysis report

Static analysis result for SHA-256 39dc3965f1e0b0f2…

MALICIOUS

PDF

111.9 KB Created: 2021-04-21 06:14:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 58e5f312bb681e8ed16288e37c927640 SHA-1: 0226852e2c398d377fcbac912dad0ec82a4e31c6 SHA-256: 39dc3965f1e0b0f28cc808fe6024c2cdad0cf0fb812ba0fcb3bfb11c7314adca
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous embedded URLs, many pointing to disposable domains or link farms, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of malicious activity, likely leveraging embedded JavaScript for redirection or exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8034

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://ambrose.edu/sites/default/files/webform/kepasibadugemefobovabo.pdf
    • https://www.natsihwa.org.au/sites/default/files/webform/zolevijovexoneda.pdf
    • https://ambrose.edu/sites/default/files/webform/61928937085.pdf
    • https://www.jts.org.jo/sites/default/files/webform/96043924660.pdf
    • https://aboss.by/sites/default/files/webform/32639212941.pdf
    • https://www.jwico.com/sites/default/files/webform/monufugabezexi.pdf
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/22559513310.pdf
    • https://www.ofalloncasting.com/sites/default/files/webform/tasuwagorefovufozibojer.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=final+fantasy+xiv+online+gameplay+2020
    • https://campusrec.princeton.edu/system/files/webform/rilawadabovoxilezevateg.pdf
    • https://printandmail.princeton.edu/system/files/webform/83605599331.pdf
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/95830943344.pdf
    • https://gradfutures.princeton.edu/system/files/webform/pelafo.pdf
    • http://scripts.sil.org/OFL

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00016fcb.bin
6e9bdb9a0dd44bb7decc2346d88e5d60a877d22b50ee8176c56a65dbcfa6f00f
pdf-font-stream PDF embedded font (sfnt) at offset 0x16FCB 4776 bytes
font_01_sfnt_off0001808d.bin
bea7af2d1805f22eee7335dfdeae291a96f270d43cfb93a59f5ee77b3d704c74
pdf-font-stream PDF embedded font (sfnt) at offset 0x1808D 5584 bytes
font_02_sfnt_off000193a4.bin
c14bd6cdf33f4d380cc2300b8f9944e4acca6b4cd51dc7a20ae57ef0f29be7bf
pdf-font-stream PDF embedded font (sfnt) at offset 0x193A4 11676 bytes