Malicious PDF — malware analysis report

Static analysis result for SHA-256 a521a4274aeac779…

MALICIOUS

PDF

72.3 KB Created: 2021-03-28 08:48:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-24
MD5: 2a1dbf657e837c43cb613e6e4bf28de6 SHA-1: efa4aaf7086302eb8abd85c049ba736ab06ade79 SHA-256: a521a4274aeac779802c52608988ee8371a7cc3063b1fa5f41e134063d8b0b5c
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 0.9996

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://druttle.ru/123?utm_term=kinship+diagram+template+free PDF link annotation
    • https://jinitemolo.weebly.com/uploads/1/3/1/8/131856214/fumifowek_bekaxadawezufaf_juteju_xasudasa.pdfIn PDF document text
    • https://bufopajej.weebly.com/uploads/1/3/5/9/135956722/fetovirezowupib_fedunukit_terexajilixuvix.pdfIn PDF document text
    • https://vofirojaj.weebly.com/uploads/1/3/1/6/131637635/3c12b433c3057.pdfIn PDF document text
    • https://jedadizonavo.weebly.com/uploads/1/3/4/7/134721040/feduxanob-xurofo-digiros-vaxilagul.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4405195/normal_6039151233e36.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393628/normal_60231665ac25e.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4366312/normal_6005f7efbbe78.pdfIn PDF document text
    • https://buxudirikebipur.weebly.com/uploads/1/3/1/1/131164004/6112953.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4499979/normal_60126456d4a07.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4474759/normal_603b948a20567.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4453551/normal_6046132c99add.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450730/normal_5fe8f4bba8f43.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/8131550e-7b08-4015-a71b-f29b7bf019c3/marisi.pdfIn PDF document text
    • https://d05b2b94-0af3-401c-a6ef-75d00d0b58ae.filesusr.com/ugd/3bca44_08e6b0b4105d428a8b685e33e861276f.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/xefezesebusu/71733552678.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8ed3b305-9914-417c-894a-0108bff55a67/38769843758.pdfIn PDF document text
    • https://s3.amazonaws.com/nonabafat/92846906720.pdfIn PDF document text
    • https://969948a0-d7f7-4827-958e-a3856fee42d4.filesusr.com/ugd/9d40bc_90bd9e225ea04b1d8ef24c0c53a816c7.pdf?index=trueIn PDF document text
    • https://a7193630-a032-4ee2-b136-33837135b76a.filesusr.com/ugd/fac845_ed537cec79454d92bf8a092ec3f5daaa.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/ebc15afa-b4df-493a-b630-50500c02e435/when_does_twilight_midnight_sun_movie_come_out.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d939660e-5e32-4ed3-9623-90c36465d610/how_to_fix_mini_humidifier.pdfIn PDF document text
    • https://s3.amazonaws.com/fosalizuzu/android_auto_spotify_playlist_sortieren.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_off0000db44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB44 5424 bytes
SHA-256: 12d6a968d7c018df39865001d0db5ee501083c0e543349c25d7a83e20e980739
font_01_sfnt_off0000ed90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED90 11292 bytes
SHA-256: 8f7c30bf891bb70313cbb1b37108fd590f5a0ec8b81bc46020cec17ba0dc6ad8