Malicious PDF — malware analysis report

Static analysis result for SHA-256 f13307a2bef52197…

MALICIOUS

PDF

108.5 KB Created: 2021-04-08 09:53:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c68e662b8e9ac9cf390987c75db52dd3 SHA-1: 71ea5daa7ca6271458bc47d2ca534adf5c068a13 SHA-256: f13307a2bef5219710aa46f6c667de7649c49be7c3ed84ff6c24bc839b2510c4
214 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a critical heuristic firing for linking to known malicious redirector infrastructure, specifically `https://yafferge.ru/wix?keyword=acs+general+chemistry+study+guide+quizlet`. Additionally, it exhibits characteristics of a PDF link farm with numerous embedded URLs, suggesting a phishing or SEO manipulation scheme. The ML classifier and ClamAV detection further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://yafferge.ru/wix?keyword=acs+general+chemistry+study+guide+quizlet
    • https://cdn.sqhk.co/doxinotilid/V6ifz4t/31393362092.pdf
    • https://cdn.sqhk.co/tivuzofep/beifggy/juridugesafo.pdf
    • https://cdn.sqhk.co/muxuzoxipopa/gwiehjL/jajufemapigumenazoj.pdf
    • https://cdn.sqhk.co/zubuwebofe/cfydhhn/live_tv_apkpure.pdf
    • https://cdn.sqhk.co/sepufaziru/jIhhhdV/charlie_s_barber_shop_ellensburg.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://907864b8-ab38-4b43-b195-7646ee37c451.filesusr.com/ugd/c4b402_4b643eb713e048dd819b483bcdc3e342.pdf?index=true
    • http://vofimefokugof.epizy.com/45382367536.pdf
    • http://koxogulu.rf.gd/desupotibizadafetoxezit.pdf
    • http://tisenunab.rf.gd/bollinger_bands_binary_options_strategy.pdf
    • https://dfa52777-3edb-460f-9b14-ca5101cd4ecc.filesusr.com/ugd/5360f8_1964ac03194c417fab3ebf13943c129a.pdf?index=true
    • http://figupowogo.rf.gd/how_to_hang_a_wooden_sign_without_nails.pdf
    • https://a0bbd489-bf03-48a0-8e93-88abd0751e5b.filesusr.com/ugd/370ea2_f2b7a1f623bb45489b7422fee0c29610.pdf?index=true
    • http://wetizizokixo.epizy.com/wixosilubipilavevukogupeg.pdf
    • https://855e1e5b-0daf-4dce-aa73-dfad2bfec5df.filesusr.com/ugd/ced2dc_65585a060a7d4fae81944e4c67c129fa.pdf?index=true
    • https://edb7bb8d-792a-4213-93ec-7f573d37cc74.filesusr.com/ugd/bfd504_f3b339105f8f46298a97de98fd6e73ef.pdf?index=true
    • https://f8071fb1-33dc-4bb9-9fe9-292e0ca0d861.filesusr.com/ugd/253000_a7f071ba9e1941949293d9cead0b6256.pdf?index=true
    • http://nodefojabotozij.rf.gd/5383996343.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://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License
    • http://scripts.sil.org/OFL

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off000178df.bin
5c0a7b0af61386c4d72159432a8e732651cbdea0140d3df54057c7c2057b88dc
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x178DF 18620 bytes
font_00_sfnt_off00013c12.bin
238275c7824803414632cdcdd5273ff19ee309b7da2f53f864399e25df8882ed
pdf-font-stream PDF embedded font (sfnt) at offset 0x13C12 5392 bytes
font_01_sfnt_off00014e27.bin
6c3487a7117ef9eaee74c386a735efcc01c973f0997d66fcdff697e0652ad9b7
pdf-font-stream PDF embedded font (sfnt) at offset 0x14E27 13272 bytes
font_03_sfnt_off00019613.bin
cd94ef65598b1866d0653cdd88243d989fd81359c0e770c2d3a4858f1c2f6d34
pdf-font-stream PDF embedded font (sfnt) at offset 0x19613 4324 bytes