Malicious PDF — malware analysis report

Static analysis result for SHA-256 49dca2ae687f4406…

MALICIOUS

PDF

76.5 KB Created: 2021-04-23 14:54:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 9e3e6b4837a4ef326938d76398e10936 SHA-1: b0eda9ee8cbcb00828c1f9d90abe3521d1659d82 SHA-256: 49dca2ae687f440619c9651a1bdbb271f1790d32dfac3e8c033cd6630e64e7c6
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, with heuristics indicating a link farm designed to direct users to various websites. The document body, though heavily obfuscated, contains text related to 'anesthesiology residency salaries' and mentions 'wkhtmltopdf', suggesting a lure to disguise malicious intent. ClamAV detection and ML classification confirm its malicious nature, likely as a phishing or malware distribution vehicle.

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://vilenefex.ru/strik?utm_term=anesthesiology+residency+salaries
    • http://dusikazo.mypressonline.com/asciidoctor_title_page_layout.pdf
    • http://xirijapip.mypressonline.com/candlestick_patterns_analysis.pdf
    • https://cdn.sqhk.co/jivazufevi/hb4UPez/zufobuvugalif.pdf
    • http://lozejebivo.scienceontheweb.net/vs_code_shortcuts_windows.pdf
    • https://cdn.sqhk.co/konanetufuda/hgjifie/fun_things_to_do_in_philly_this_week.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://f2fffe36-c7b4-4b88-9608-518dc6c14750.filesusr.com/ugd/950b2a_cdd130c842b447e6b6984c71d182a8ff.pdf?index=true
    • https://s3.amazonaws.com/gonima/janus_capital_group_annual_report.pdf
    • https://s3.amazonaws.com/geraromu/86774600191.pdf
    • https://s3.amazonaws.com/sefukirexuwekij/what_were_mesopotamians_known_for.pdf
    • https://s3.amazonaws.com/xifabilejilab/ronutomisetejugowomo.pdf
    • https://s3.amazonaws.com/litunux/69549774504.pdf
    • https://s3.amazonaws.com/lezopobigeza/xekotumetuxuv.pdf
    • http://pexirud.onlinewebshop.net/hvac_test_questions_and_answers.pdf
    • https://s3.amazonaws.com/rixevozajixezos/55934463989.pdf
    • https://cccd2283-d272-450a-840b-6541230ebad2.filesusr.com/ugd/5de1df_f1dfa8562aca48a48fa00f2a17b876bc.pdf?index=true
    • https://s3.amazonaws.com/kukazowox/79928058090.pdf
    • http://junaken.onlinewebshop.net/baixar_o_foxit_editor.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_off0000ecfb.bin
74ecfa501fd196c0473eced6633c4cff2c18f0429fd2f85e8b6961eea7b1850b
pdf-font-stream PDF embedded font (sfnt) at offset 0xECFB 5292 bytes
font_01_sfnt_off0000fefd.bin
e2432d0f9afae2bbf3a3c6f1dcc8b1673c1e7c3d9a61727842484fdbf0da6aec
pdf-font-stream PDF embedded font (sfnt) at offset 0xFEFD 11148 bytes