Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f9397c1aa2e12fe…

MALICIOUS

PDF

68.2 KB Created: 2021-03-05 19:53:32 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-17
MD5: ab48c46265abb2e1dbdc928012b0bc2b SHA-1: 48eaeaaf42ca1107282351967667e3d58faafb97 SHA-256: 3f9397c1aa2e12fee09d268bd2fdc4e4719f8fe12ee7ec621751df3d4a6c1959
186 Risk Score

Malware Insights

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

The PDF document contains a large number of external links, many hosted on disposable domains, suggesting a link farm or phishing attempt. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body, though heavily obfuscated, appears to be a lure for educational materials, directing users to external URLs like https://bologen.ru/strik?utm_term=pearson+edexcel+international+as%252Fa+level+biology+student+book+1+pdf+free.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • 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 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.
  • 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://bologen.ru/strik?utm_term=pearson+edexcel+international+as%252Fa+level+biology+student+book+1+pdf+free PDF link annotation
    • https://cdn.sqhk.co/simikitivo/frtjalD/vumofejufanor.pdfIn PDF document text
    • https://cdn.sqhk.co/gejupajo/jgE8eZr/85526630968.pdfIn PDF document text
    • https://cdn.sqhk.co/timafewa/Maqidhi/juzasel.pdfIn PDF document text
    • https://pesakezered.weebly.com/uploads/1/3/4/7/134729162/gefosekulevisem.pdfIn PDF document text
    • http://nenonazuf.scienceontheweb.net/kelufelog.pdfIn PDF document text
    • https://fekanarikivokil.weebly.com/uploads/1/3/4/8/134884633/6469862.pdfIn PDF document text
    • https://cdn.sqhk.co/pelotuwew/gge8hf3/11588421806.pdfIn PDF document text
    • https://didekupava.weebly.com/uploads/1/3/1/1/131163833/502ed7178c9fb5.pdfIn PDF document text
    • http://dakisemakegag.sportsontheweb.net/werowuvog.pdfIn PDF document text
    • https://cdn.sqhk.co/vuvesanap/Rjcjgii/44505291181.pdfIn PDF document text
    • https://cdn.sqhk.co/wularumijif/gi9AhfK/10431535428.pdfIn PDF document text
    • https://cdn.sqhk.co/janawezexoj/c1ZKIhT/48992396473.pdfIn PDF document text
    • http://faxixovojaja.sportsontheweb.net/maxezivonipepumetafi.pdfIn PDF document text
    • https://cdn.sqhk.co/rapekerokemo/qijVgiP/lelumino.pdfIn PDF document text
    • https://pamuguvijokogag.weebly.com/uploads/1/3/4/8/134883264/foxesedazusi.pdfIn PDF document text
    • https://fewurigog.weebly.com/uploads/1/3/0/9/130969621/rodemudiluju_pukibonalivuro_pupej_wojezusaj.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://a1359116-1358-4cde-afc5-3600b4bb50db.filesusr.com/ugd/3b0c81_671ffd865fba42cfb67f20eecb984f1f.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/0d8acb97-bc20-435c-90cb-87b116ef4775/tom_browns_wilderness_survival_guide.pdfIn PDF document text
    • http://nujugeteteda.myartsonline.com/clothing_donation_drop_off_near_me_during_covid.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c824a0d4-6f4d-431e-91b7-5dbc57fa2c14/mikanoxopiw.pdfIn PDF document text
    • https://80b1f93a-fe74-4439-a81d-34814fa7a505.filesusr.com/ugd/e56fe2_3c196d5c24534855a107c3a73a7ad3c1.pdf?index=trueIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cc05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC05 5848 bytes
SHA-256: 594e74e754286410f38c0ad1c5d574629240a87ffb03a51679e998bde4506f79
font_01_sfnt_off0000e019.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE019 10200 bytes
SHA-256: 9ae263ebcae9ed604d359a74b0cd842dbdd51de7c54d40c3172a65b763aab451