Malicious PDF — malware analysis report

Static analysis result for SHA-256 3950cb4ac76f1f35…

MALICIOUS

PDF

79.4 KB Created: 2021-03-15 22:16:50 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-07
MD5: f7fa06c82fb0cad46a3458de9e7fdd36 SHA-1: 8d4f3bd2a1ad221bf73cce2353333410cd6087b5 SHA-256: 3950cb4ac76f1f352cbe203584834e5a4ef37d7672f7cce85e66a6987cd2b2f8
252 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of embedded links pointing to external PDF files, many hosted on disposable domains or known redirector infrastructure. This behavior is indicative of a link farm, likely used for SEO manipulation or to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, and the presence of numerous external links aligns with techniques used to spread malware or phishing lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://dafemum.ru/wix?keyword=1+click+video+site+builder+pro In PDF document text
    • https://cdn.sqhk.co/numorolele/ibeWqkF/56268860764.pdfIn PDF document text
    • https://cdn.sqhk.co/gudijupimeb/Ogd76if/escape_proof_cat_harness_amazon.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4416811/normal_5feeb2c6e9110.pdfIn PDF document text
    • https://cdn.sqhk.co/kalusoxat/lM8LhcL/retro_car_racing_arcade_games.pdfIn PDF document text
    • https://cdn.sqhk.co/nozelenid/Lhhhaia/fukatasixadoxopojufixit.pdfIn PDF document text
    • https://cdn.sqhk.co/lojosewude/ChfGolO/xisilowilegetavivesulewo.pdfIn PDF document text
    • https://devigumekumowir.weebly.com/uploads/1/3/4/3/134394761/9409907.pdfIn PDF document text
    • https://mobiduretul.weebly.com/uploads/1/3/4/6/134681609/karaguv-xugimi-burufififo.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4384644/normal_60417510c7c16.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4372963/normal_5ff5716c19e46.pdfIn PDF document text
    • http://bewaniv.22web.org/how_to_make_a_fitted_face_mask_with_free_pattern.pdfIn PDF document text
    • https://xevirurij.weebly.com/uploads/1/3/4/3/134357690/8001984.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://rujepomekelad.rf.gd/ist_monster_energy_ultra_vegan.pdfIn PDF document text
    • http://gaditerigasut.rf.gd/another_day_in_paradise_font.pdfIn PDF document text
    • http://wasizematimom.rf.gd/98614941715.pdfIn PDF document text
    • https://a39ac558-8fe8-437d-9e10-dc9402d6cb9c.filesusr.com/ugd/1ebe14_0eb2259700fb4c51af481ede32494b9f.pdf?index=trueIn PDF document text
    • http://kupavojos.epizy.com/airasia_group_berhad_annual_report.pdfIn PDF document text
    • https://367e539a-c541-4439-991c-4bf2bef2aa7a.filesusr.com/ugd/77d535_b6edeaa843c149f2a82aa27b37ec8725.pdf?index=trueIn PDF document text
    • http://popavager.epizy.com/votomawugogulipunuf.pdfIn PDF document text
    • http://wetexop.rf.gd/torolafidiwokuruwotos.pdfIn PDF document text
    • https://b00f38ea-0d13-4519-ab0f-1253f0d03ca0.filesusr.com/ugd/289c5e_9332159918a947f5813454686b1e87a8.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_off0000f98a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF98A 5076 bytes
SHA-256: c22067ea9e5b4fbccbdbc4c639a0337f9786caad1ee5839f7b888eed40d0b213
font_01_sfnt_off00010ae1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AE1 10976 bytes
SHA-256: 7c0ac2c1a4df82a35f4bee4f28ae1b6e8d83e17f6186a07539032ec544450075