Malicious PDF — malware analysis report

Static analysis result for SHA-256 b6a343b37da4d8e3…

MALICIOUS

PDF

73.3 KB Created: 2021-03-02 12:53:10 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 3c9111ce0034881351d52cef8eae24bb SHA-1: ec5aa98790f3350f2f23e6df1f33ea1fe51b9c85 SHA-256: b6a343b37da4d8e3f9d80c63d83bfc16305e7a8d1719080aaf1f2bc81ecf0bb1
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, and contains a large number of external links, indicating a link farm or phishing attempt. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, and the presence of numerous external URIs points towards a malicious intent to redirect users. No scripts were extracted, but the PDF structure itself facilitates the redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://soxebez.ru/wix?keyword=donald+davis+football
    • https://cdn.sqhk.co/zexupibo/gZUjudd/marketing_strategies_of_social_media_sites.pdf
    • http://shop-you.xyz/vawumaloragegunib6frz0.pdf
    • https://cdn.sqhk.co/wifopuzuxiba/hbQYwXO/japanese_auto_spare_parts.pdf
    • http://xiwasaruv.66ghz.com/mosuwitozano.pdf
    • https://foramawebor.weebly.com/uploads/1/3/1/4/131410370/sujufiduki.pdf
    • http://frasqen.online/read_crescendo_online_freewzawy.pdf
    • https://cdn.sqhk.co/pubamegumox/dEahjhc/46135297621.pdf
    • https://cdn.sqhk.co/luwibajik/jcgg78p/wosojem.pdf
    • http://maddot.space/frases_de_atticus_matar_a_un_ruiseorijo0d.pdf
    • https://cdn.sqhk.co/vagofedewat/cFheXWX/97760135217.pdf
    • https://worudunomazife.weebly.com/uploads/1/3/1/4/131483266/5987362.pdf
    • http://copyright-securityx.com/niferegexifuja85ps7.pdf
    • https://deremufirig.weebly.com/uploads/1/3/4/8/134854029/5064356.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/webipejonavuv/appendix_fm_form.pdf
    • http://zamewoj.rf.gd/word_family_list.pdf
    • http://bikaxubu.rf.gd/rowdy_baby_hd_video_free.pdf
    • https://s3.amazonaws.com/xomepixo/51511147504.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e35d.bin
a243f52e58a04661db1d4699dde1736af4dc9eb55522d6534a4d7d47fda137f6
pdf-font-stream PDF embedded font (sfnt) at offset 0xE35D 5004 bytes
font_01_sfnt_off0000f47f.bin
9055ac3e76ff92d4dbe33b445885b81d29e8c4e28405a599fb2f0f7ec5490b24
pdf-font-stream PDF embedded font (sfnt) at offset 0xF47F 10560 bytes