Malicious PDF — malware analysis report

Static analysis result for SHA-256 61630690c5b8dc67…

MALICIOUS

PDF

81.4 KB Created: 2021-04-28 21:46:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: d2f79e6bd8fc5bc79b161f78aa2b1cb5 SHA-1: 8edb6822136b85a7c8dd73bf28f030b15fe10e90 SHA-256: 61630690c5b8dc6752590cd79c2c4ecbc41c3f1fbb7ec3f339da797c9d12a901
196 Risk Score

Malware Insights

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

The PDF contains numerous external links, with a significant number pointing to an SEO redirector disguised as a free textbook download. The heuristic 'PDF_SEO_LINK_FARM' indicates a large number of such links, and 'PDF_SEO_UTM_REDIRECTOR_LINK' specifically calls out the free-download phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution.

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://soxebez.ru/strik?utm_term=anatomy+and+physiology+textbook+for+medical+students PDF link annotation
    • https://cdn.sqhk.co/nugutobudan/ieFjhOB/70419927248.pdfIn PDF document text
    • https://cdn.sqhk.co/soxuxopova/hbC83jg/bejiwiraxifelomafimuto.pdfIn PDF document text
    • http://cg-designer.xyz/where_is_the_battery_for_a_2005_chevy_equinox4zt4g.pdfIn PDF document text
    • https://cdn.sqhk.co/rufopunuk/gihjKjc/funny_summer_captions_for_instagram_with_friends.pdfIn PDF document text
    • http://devgm.design/how_to_clean_a_browning_2000_shotgun2mmzx.pdfIn PDF document text
    • https://cdn.sqhk.co/rogolafu/ghzRIgi/natapogobesudiverutuvo.pdfIn PDF document text
    • http://zenizumalem.22web.org/jovixixalarezakibesegil.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/tiniruru/jatugikibofofukex.pdfIn PDF document text
    • https://696f1bd8-06c3-47a7-a8f7-e83e17ec8d18.filesusr.com/ugd/5ad03d_799fa18cb0944ef78021221fd9fca90a.pdf?index=trueIn PDF document text
    • https://e9593579-f51f-4dc6-af55-2543ab512b45.filesusr.com/ugd/37952c_ad60e9869d404df8beea62c227e03419.pdf?index=trueIn PDF document text
    • https://1b3fde16-7575-45ba-b40e-8916c64185ca.filesusr.com/ugd/8874e8_cc0b68f4adfd40d89fc1698f3e022902.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/latufenaw/new_version_of_google_chrome_for_android.pdfIn PDF document text
    • https://a519209a-2b0a-481f-9fe9-460c873bdc80.filesusr.com/ugd/270e53_1bcce4f0208441d590b0ae71d520f2fd.pdf?index=trueIn PDF document text
    • https://981168d4-05fc-44b6-871d-73371d7e8cf1.filesusr.com/ugd/87d215_5249a17493ae4a1a961fe534b3a70210.pdf?index=trueIn PDF document text
    • https://b3a8b944-ddec-4d17-9b53-5a1c05c66d8c.filesusr.com/ugd/314503_1ff6c9f558154f7c9426cb5c11ae5975.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/gomakobez/64160379063.pdfIn PDF document text
    • https://5d94d51b-2702-4b64-8df3-eadd022f3edc.filesusr.com/ugd/2ddd39_48471693b2cf4ba0b40057505722cbc5.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/kagedatabujo/72787081510.pdfIn PDF document text
    • http://nitusubor.rf.gd/mr_chips_full_movie_free.pdfIn PDF document text
    • https://s3.amazonaws.com/wisuw/kigigibademujonugawagito.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_off0000ffde.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFDE 5932 bytes
SHA-256: 557bb16aaa444fc52740c40c01991ff3b01a3defdc6ad13568a7877985ca18f4
font_01_sfnt_off000113f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113F7 10504 bytes
SHA-256: cbd28f478e0e9e356406a43ea30d44cddf49a7fe3f5b098ff2544424107bc20e