Malicious PDF — malware analysis report

Static analysis result for SHA-256 847a4997946642dc…

MALICIOUS

PDF

78.4 KB Created: 2021-03-15 16:40:24 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-17
MD5: 2227a8b8fc08384b1830c748bb0d93da SHA-1: 27369997e6ae996410d283b4f495148ff4e82ddc SHA-256: 847a4997946642dc75fd2fec2fb560ddad323d303bfc8399bc317406b7b9ca58
186 Risk Score

Malware Insights

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

This PDF document functions as a link farm, directing users to numerous external websites under the guise of providing 'English grammar books for college students'. The heuristic firings indicate a high volume of external links, many hosted on disposable domains, suggesting a malicious intent to drive traffic for potentially fraudulent purposes. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a phishing or spam campaign.

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=english+grammar+books+for+college+students PDF link annotation
    • https://cdn.sqhk.co/zovitamojim/fhidBQR/cable_size_calculator_uk_12v.pdfIn PDF document text
    • https://cdn.sqhk.co/potiribuwuf/ie0H7eR/48788875880.pdfIn PDF document text
    • https://cdn.sqhk.co/gawukale/VtI8nzB/princess_hair_beauty_salon_rochdale_ol16_1rx.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387709/normal_5fd82d173cc2e.pdfIn PDF document text
    • http://dupamineni.medianewsonline.com/the_lord_of_the_rings_the_fellowship_of_the_ring_extended_edition_vs_theatrical.pdfIn PDF document text
    • https://masenajeronuzes.weebly.com/uploads/1/3/1/6/131637464/vililazef_pomivebopuvatab_fidaxezugi_saxamarupobi.pdfIn PDF document text
    • https://wifevotus.weebly.com/uploads/1/3/4/8/134897576/poleriravafepafe.pdfIn PDF document text
    • https://vumukawa.weebly.com/uploads/1/3/4/6/134662430/kepamusixifogul-vewiwoxabu.pdfIn PDF document text
    • http://nuredalad.iblogger.org/lofavefezijuselubepexa.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4409797/normal_604d179cb28af.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4496592/normal_600bbdc7c54da.pdfIn PDF document text
    • https://gipasutojemozup.weebly.com/uploads/1/3/1/3/131379868/7718517.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4482406/normal_6047b5d34adce.pdfIn PDF document text
    • http://dosaxixapaxa.medianewsonline.com/wojazatutuja.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4389797/normal_604f5f9f85afd.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://b6086c54-8ef4-40f3-ba18-bbbb993b339e.filesusr.com/ugd/36e927_59b0d8bb725345d79a19ef7ab9add53d.pdf?index=trueIn PDF document text
    • https://ff8eac81-0dee-4da4-b7c1-1dee070544a7.filesusr.com/ugd/2637cf_fb57fb02b2544344b39c928672f0e2e0.pdf?index=trueIn PDF document text
    • https://99516632-72ce-40f3-a9a1-a01c91361c65.filesusr.com/ugd/e42c35_d3c02056090a462d9f2002f3fcd775f8.pdf?index=trueIn PDF document text
    • https://1c514d3f-4aca-4c14-a2cc-94ef866bc6c7.filesusr.com/ugd/860217_bc493a8c1ed048228082c9cb51cd5953.pdf?index=trueIn PDF document text
    • http://jowunimigafej.rf.gd/nogikusamufusilofoluper.pdfIn PDF document text
    • http://juborekif.atwebpages.com/wugosama.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_off0000f1f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1F0 5596 bytes
SHA-256: 68f0815823454564c4348c6d8a4ebc3d8de1ffbafdfb82bdc5abe54a52f94dc6
font_01_sfnt_off000104d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104D2 11616 bytes
SHA-256: 02951985a0f37630eff21cc78ca028e3166e0734473be31d13088c9d3ded303c