Malicious PDF — malware analysis report

Static analysis result for SHA-256 821e52c5861c1e8d…

MALICIOUS

PDF

91.1 KB Created: 2021-03-15 09:38:13 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-17
MD5: d839b37c6a4b86bafa73d761349bcc0c SHA-1: 28365c79edbf418646d7da9f73fe75acc9f2be0c SHA-256: 821e52c5861c1e8df74aabb8799fa065d03a68621c560c9a30287f5827a38aea
126 Risk Score

Malware Insights

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

The file was detected as a malicious PDF by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, with at least one pointing to a domain associated with link farming and disposable hosting, suggesting a phishing or malware distribution scheme. The presence of embedded JavaScript, though not directly executable in this context, is a common technique for exploiting PDF vulnerabilities or redirecting users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://xajibur.ru/wix?keyword=properties+of+real+numbers+worksheet+with+answers+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4487902/normal_6042d8e7f0f5f.pdfIn PDF document text
    • https://cdn.sqhk.co/suwapipejob/CMcgzhd/survival_rate_of_pancreatic_cancer_after_whipple_surgery.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366312/normal_6043fd8ae2d20.pdfIn PDF document text
    • https://cdn.sqhk.co/wejupexuput/cicdhU3/273550544.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383470/normal_603e3043bb18d.pdfIn PDF document text
    • https://cdn.sqhk.co/matikefateri/dij9ifP/winter_bucket_list_with_friends.pdfIn PDF document text
    • http://yatvoyya.fun/bipolar_junction_transistor_experiment_reportq06w5.pdfIn PDF document text
    • https://cdn.sqhk.co/dopebuxoz/gAU4gjO/adult_coloring_books_walmart.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4393762/normal_5ffc48e38b4f2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4391909/normal_5fe7df0f9b719.pdfIn PDF document text
    • http://boevoenlp.com/907721440951u8fx.pdfIn PDF document text
    • http://mumolazesinidix.getenjoyment.net/can_you_improve_non_verbal_reasoning.pdfIn PDF document text
    • http://tukomibewi.getenjoyment.net/zelivojebakatenetiremez.pdfIn PDF document text
    • http://shoppingyxplus.xyz/physical_development_activities_for_18-24_monthsmuu37.pdfIn PDF document text
    • https://cdn.sqhk.co/kisasizaro/aginouQ/49677491020.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4411683/normal_5ffb766ead087.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4503035/normal_5fd8965883bd5.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/ca682507-97e7-47ba-aad6-17a22b5ac3ad/apollo_twin_quad_mkii.pdfIn PDF document text
    • http://kubomefewofumim.atwebpages.com/45760126378.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8fe0a112-24b6-4852-9b27-34177b352aa9/questions_to_make_you_fall_in_love_reddit.pdfIn PDF document text
    • http://futikuzita.onlinewebshop.net/75642200479.pdfIn PDF document text
    • http://bamonoxo.onlinewebshop.net/libro_de_fisica_3_secundaria.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bc432ca3-4c88-4445-ae26-7fadd025c6dd/99421454269.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f72a45ae-af29-4c45-9816-3df714d30612/34242929985.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8b6564a9-af5d-48a4-8a46-fef4dc92a7ba/jofowikedurer.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010cf4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CF4 5580 bytes
SHA-256: eecff6cebe3c2ad9ee7fd5aefdb11b27b822534536b6f10a3cfd661e9d2e3172
font_01_sfnt_off00011fca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FCA 11724 bytes
SHA-256: 018e7cd43d3a49804e3aba14023360f757c49019fc1cd5625b53ace2c5d620f2
font_02_sfnt_off000147ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x147EA 16304 bytes
SHA-256: 3a69d5d6270cfe5c51c2d508c72ec88318e56069af2b6a6a4416d06009d582f5