Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b3f9165584d75a5…

MALICIOUS

PDF

77.9 KB Created: 2021-03-20 21:28:54 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-23
MD5: 7b91eaf2191c2c2546b3556a3d98f5a0 SHA-1: 28bb78f207fb628475c254ea83206bd02efc4b21 SHA-256: 3b3f9165584d75a522ea1ed75348bc5804c8563bb57f5b853a1c840452fc6bc4
244 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, many pointing to external PDF files hosted on disposable domains, indicating a link farm or SEO manipulation tactic. Critical heuristics identified the PDF as a malicious redirector and a link farm, with ClamAV detecting it as a phishing trojan. The ML classifier also strongly flagged it as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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
  • 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.
  • 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://crophysi.ru/award?keyword=estudo+sobre+atos+dos+ap%25C3%25B3stolos+pdf In PDF document text
    • https://nimopiwezu.weebly.com/uploads/1/3/4/7/134700470/9976850.pdfIn PDF document text
    • http://xapidomin.mywebcommunity.org/xegasufexoxeguwov.pdfIn PDF document text
    • https://cdn.sqhk.co/furikute/j1iiHhj/anime_dress_up_avatar_maker.pdfIn PDF document text
    • http://dajewerudo.22web.org/50567867170.pdfIn PDF document text
    • https://gumotijilazu.weebly.com/uploads/1/3/1/6/131637190/wipefonufilagiv-dujevisar-jifenolepowom.pdfIn PDF document text
    • https://goponubinolofuv.weebly.com/uploads/1/3/4/6/134695307/9821246.pdfIn PDF document text
    • https://penoruzeni.weebly.com/uploads/1/3/4/1/134132400/2764ace4.pdfIn PDF document text
    • https://fekugutupufug.weebly.com/uploads/1/3/4/8/134876907/vaseterogujuguveseka.pdfIn PDF document text
    • https://cdn.sqhk.co/zuxolusufa/egiQiap/bubuzevakorofikijusosori.pdfIn PDF document text
    • https://medefidonirefej.weebly.com/uploads/1/3/5/3/135324812/b8939f26edf2.pdfIn PDF document text
    • https://cdn.sqhk.co/navimoxa/Cgcje7Y/woleniw.pdfIn PDF document text
    • http://womizepivilora.sportsontheweb.net/64213292476.pdfIn PDF document text
    • https://netexebi.weebly.com/uploads/1/3/0/8/130815192/rabiw.pdfIn PDF document text
    • https://komimuvupelogi.weebly.com/uploads/1/3/4/3/134312664/desulenugal.pdfIn PDF document text
    • https://cdn.sqhk.co/nulegudup/jioqCoA/convert_into_word_i_love.pdfIn PDF document text
    • http://fajujefa.getenjoyment.net/atp_photosynthesis_and_cellular_respiration_webquest_answers.pdfIn PDF document text
    • https://gamevuwi.weebly.com/uploads/1/3/4/5/134525912/gagotixufe.pdfIn PDF document text
    • https://cdn.sqhk.co/jubawiwa/hgG29ij/61993783418.pdfIn PDF document text
    • http://totipuzuforaz.mywebcommunity.org/beauty_salon_services.pdfIn PDF document text
    • https://fojevuresuzuj.weebly.com/uploads/1/3/4/8/134881640/fajugomanoxitexijis.pdfIn PDF document text
    • https://sigipobixa.weebly.com/uploads/1/3/1/6/131606309/d25e5f.pdfIn PDF document text
    • https://susokeruno.weebly.com/uploads/1/3/4/6/134656617/robufuzaraluxixap.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://raxegujanamefas.atwebpages.com/how_to_play_mastermind_rogue.pdfIn PDF document text
    • http://bejopirobi.epizy.com/46100781183.pdfIn PDF document text
    • http://detuzepa.rf.gd/beginner_piano_sheet_music_free_printable.pdfIn 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_off0000ede7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDE7 5268 bytes
SHA-256: 5c56abbe31190d4db27d3181f5b2f6216dfbce0343c54694854a80bf68270aff
font_01_sfnt_off0000ff99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF99 13180 bytes
SHA-256: e301eb0fdd7920598a15cf893d16141fa506725ab2ff537950c6eebea8294ad9