Malicious PDF — malware analysis report

Static analysis result for SHA-256 528aaf0e40042d57…

MALICIOUS

PDF

76.5 KB Created: 2021-03-15 13:06:21 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: f3e064468b79ed60b467d61e0d84e6d3 SHA-1: 491cbadc82006efcfc6b7390065183a10f059017 SHA-256: 528aaf0e40042d57a7051685d00236f672343c62694273eb3e5463a4a5ec63a2
196 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many of which are part of an SEO link farm. One prominent link, disguised as a thermostat manual, redirects to a malicious URL that appears to be part of a phishing or SEO scam. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://nipisod.ru/wix?keyword=east+providence+school+bus+schedule+2019 PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4370088/normal_5ffd492275615.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4417818/normal_5ffc392d35114.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4478393/normal_600d66361f035.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4374689/normal_602f2be1e6a74.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387933/normal_603eb3a6e90e2.pdfIn PDF document text
    • http://chempion.coffee/bipobutj2odz.pdfIn PDF document text
    • http://thecaffeinatedstudent.com/getting_from_college_to_career_epubbso5l.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://uploads.strikinglycdn.com/files/4b9a1582-d735-4e93-98b0-ea3026469500/lux_pro_heating_and_cooling_lever_thermostat_manual.pdfIn PDF document text
    • https://s3.amazonaws.com/fejakixoweka/sevisibiwizedagevaxunor.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/224be964-706b-4afb-9634-05b97abf90b8/how_to_apply_for_planet_fitness_membership.pdfIn PDF document text
    • https://s3.amazonaws.com/tabobujimo/kewevokuzegafeso.pdfIn PDF document text
    • https://c03439ef-6557-4199-865e-586791a52b6c.filesusr.com/ugd/6bb4a2_a9e66ee918984c198197668ccaf5e0c2.pdf?index=trueIn PDF document text
    • https://17673d3b-e5d0-4e0e-8211-f079fadf35f5.filesusr.com/ugd/13ae68_4d69e686d2844b1e9dba6bd804898f2f.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/lolijexejomak/86846175189.pdfIn PDF document text
    • https://s3.amazonaws.com/dugibabafod/tepuru.pdfIn PDF document text
    • https://91c7bc9f-df77-4dbd-ae51-8bcf521f3e61.filesusr.com/ugd/1df9ea_ce1d1cbe719942afb7d34f76ad0631e6.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/xezujuxoz/employment_provident_fund_form.pdfIn PDF document text
    • https://98771922-91e4-4673-aa0d-7794f4435593.filesusr.com/ugd/b6aaa0_906fefcba69b46d79e79698438c514aa.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/guwutivupudutu/73006589177.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b68ba185-2043-4300-999a-68dd05f54c66/mulipatebesezanu.pdfIn PDF document text
    • https://s3.amazonaws.com/godoremitiwuja/tefujiritapaf.pdfIn PDF document text
    • https://cc6d8859-fc08-4100-a073-55b48c5addfc.filesusr.com/ugd/238140_c494b0190ccf41dea4342b1f505b35df.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dfa3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFA3 5680 bytes
SHA-256: f944a6967483bb3a8b9c82180b5bed52abd4d127e4f515af3c74c99a7f19c1fd
font_01_sfnt_off0000f2f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2F0 10376 bytes
SHA-256: 95d0eb6ea4f74f427951a95aee24a8ca28a44c970c01518ae80704f0bbb175b2
font_02_sfnt_off00011685.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11685 4324 bytes
SHA-256: 1062cd8ddf90f4344fa193b395386d5669df1a952e5759311ca261a71931f361