Malicious PDF — malware analysis report

Static analysis result for SHA-256 7c597a378ec1b79e…

MALICIOUS

PDF

81.1 KB Created: 2021-04-25 13:55:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: caa49f95bc6b4c7cf53c170926f12838 SHA-1: 78d587db3d7960666eb0fb75c97f86784a957727 SHA-256: 7c597a378ec1b79ed10fe75692510abc0855abfc2a43c14cbae138e18b2817a8
196 Risk Score

Malware Insights

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

The PDF file contains numerous external links, with a critical heuristic identifying it as a link farm designed for SEO phishing. One prominent URL, 'https://vilenefex.ru/strik?utm_term=apush+review+questions', is flagged as a redirector, suggesting a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or trojan delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://vilenefex.ru/strik?utm_term=apush+review+questions PDF link annotation
    • https://raxuzorozejataw.weebly.com/uploads/1/3/4/0/134042373/9245662.pdfIn PDF document text
    • http://pedagodogiko.getenjoyment.net/qualitative_and_quantitative_research_sampling_strategies.pdfIn PDF document text
    • https://besunuvoduzusub.weebly.com/uploads/1/3/4/2/134266379/tazisolemoloti.pdfIn PDF document text
    • http://kunujunekedi.mygamesonline.org/lujavewaxaxoz.pdfIn PDF document text
    • http://ruzamaji.getenjoyment.net/dupematugejowabiweripo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://8aefc570-8454-48c3-bb63-d4d1067b7ce0.filesusr.com/ugd/5c9621_35820da14d8943adaf8815afa0f82b03.pdf?index=trueIn PDF document text
    • https://dacf5b84-f80e-4bd8-bb7f-22aad20a1cd8.filesusr.com/ugd/285be4_bf998ff230d9463ab85a02ccfb1dbf34.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/xuvamuba/how_do_i_connect_my_mini_dv_camcorder_to_my_computer.pdfIn PDF document text
    • https://s3.amazonaws.com/solonebosop/samsung_galaxy_note_3_charger_adapter.pdfIn PDF document text
    • https://9e77dbea-16d6-438e-9859-4a68c5388828.filesusr.com/ugd/3225da_75f64ca121cb45a7aaa5906f15633d06.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/xakapudakadu/50006145180.pdfIn PDF document text
    • http://kabuzore.atwebpages.com/whirlpool_water_softener_cleaner_home_depot.pdfIn PDF document text
    • https://s3.amazonaws.com/nakevoja/instalacin_de_gas_domiciliario_cochabamba.pdfIn PDF document text
    • https://37523d11-79cf-4eb3-ada4-f05de57c71ee.filesusr.com/ugd/275374_4458079002a34e1487affa12fefbce26.pdf?index=trueIn PDF document text
    • https://0ecef3a8-5193-4df1-8dcb-1b7dd0f2be2a.filesusr.com/ugd/e6092c_8d65631e29af450493e709934565df2b.pdf?index=trueIn PDF document text
    • https://cc6d8859-fc08-4100-a073-55b48c5addfc.filesusr.com/ugd/238140_b1c5b6d30ea74ef399fb6a091862bf5d.pdf?index=trueIn PDF document text
    • https://0871aee9-3606-4a7a-9cba-3f178196ff53.filesusr.com/ugd/0182ef_85458a5b560a441081b6bcc9ea2d3757.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/nevovumowa/bumadazawabab.pdfIn PDF document text
    • https://00c0516a-c822-4344-a779-6f74e039753d.filesusr.com/ugd/9e41f0_e25919c9d48049a0b492fa10ba7c019e.pdf?index=trueIn PDF document text
    • https://ce2645ba-e89a-43d5-afff-5c0150757291.filesusr.com/ugd/c63dba_b2cb5d0f20fe41a2a35dfc43c8ba247d.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_off0000ffd5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFD5 4932 bytes
SHA-256: 99f3e11c622e91f539fe947db2007ff35eb7004958a0d1f1d40d1f6709c6c2d2
font_01_sfnt_off000110af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110AF 10864 bytes
SHA-256: 0741945e7770b34eaeeba6a810fdc03c9b7c7d1a2335c0af74efd7017049ed67