Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5389dbe281f7936…

MALICIOUS

PDF

80.9 KB Created: 2021-04-08 00:28:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-22
MD5: 14b6ca16e2854c551a9dd425eac90fad SHA-1: df9ae94c1fcf120f5b1f127c45a45a0027dc31ee SHA-256: c5389dbe281f7936a6a46ac7eca27276b83290af9670cd5e1c4f7d4b638541f6
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://jacksth.ru/strik?utm_term=fe+mechanical+practice+problems+for+the+mechanical+fundamentals+of+engineering+exam+pdf PDF link annotation
    • https://cdn.sqhk.co/xawobovuji/jjaShiH/picsart_photo_studio_app_download.pdfIn PDF document text
    • http://biweekamnf.com/viradozusapiroxasipomikkvl57.pdfIn PDF document text
    • https://cdn.sqhk.co/modonasuje/jFhd9Su/23687707566.pdfIn PDF document text
    • https://cdn.sqhk.co/raxedaninaso/JOtgiic/gopaminudul.pdfIn PDF document text
    • http://gsmall.space/pipoziluxegezdhyil.pdfIn PDF document text
    • http://hhizmet.com/asian_literature_historykr8s5.pdfIn PDF document text
    • http://lnstagramverifiedsbadgeforms.com/diary_of_a_wimpy_kid_new_movie_20204pjr1.pdfIn PDF document text
    • http://lightly.store/bemuvotexowepisurebup9wsi.pdfIn PDF document text
    • http://epaytds.xyz/dakiladewa9f01i.pdfIn PDF document text
    • https://cdn.sqhk.co/noxibogalu/gdhKzjd/sixodolufupokotejuxa.pdfIn PDF document text
    • http://samyog.ru/wipijg4tn9.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://45ae50e1-98a8-4501-9ad6-fc0df438eb43.filesusr.com/ugd/b16523_758c9ba8b4324647b1114b1f49bfb37e.pdf?index=trueIn PDF document text
    • https://b67fa923-03b4-4d21-b555-95ff628d7525.filesusr.com/ugd/1d4b90_aa5a7192d91c491fba5f3178706c4d20.pdf?index=trueIn PDF document text
    • https://0b21792c-a699-4cf4-8833-5910c6ad58af.filesusr.com/ugd/b0b521_49533283d8eb48a192e49fdace18b575.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/purawuma/charlie_and_the_chocolate_factory_full_movie_online_free_dailymotion.pdfIn PDF document text
    • https://160e4e15-e27a-4ef2-9b26-f67fc0969a86.filesusr.com/ugd/cbdbb6_05863850ac0d4710bca965284f6346be.pdf?index=trueIn PDF document text
    • https://9e1e9198-0fe7-4103-8084-fdcc6befb8d5.filesusr.com/ugd/2f7815_c1d1f8f394624c5abcb0f31df5624b5f.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/kawotexulozax/lasko_5586_digital_ceramic_tower_heater_manual.pdfIn PDF document text
    • https://s3.amazonaws.com/pujinit/carlsbad_caverns_fact_sheet.pdfIn PDF document text
    • https://6f12065f-c45d-410c-b048-6ec23fb2b810.filesusr.com/ugd/02ccf7_158798ffd33f4bffb450de8b1759f8c6.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/tetenifeme/absence_from_work_certificate_template_psa.pdfIn PDF document text
    • https://4f65703b-d4c0-4c9c-9e30-73c8cc83ec5d.filesusr.com/ugd/54fa57_1a3c2ebf25a44c9c9e439d0d709274e7.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/fomaralunex/23797034133.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_off0000f985.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF985 5732 bytes
SHA-256: 4850dd54c92fafee9f4cb64e8e16af9d17016124fcdc1eb16788b8d8f8ceee01
font_01_sfnt_off00010ce0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CE0 11744 bytes
SHA-256: e54784423af19b1e0b79268318862c7b473de8774d48339f13b3bd76d3230ae4