Malicious PDF — malware analysis report

Static analysis result for SHA-256 a257707b81e83035…

MALICIOUS

PDF

85.8 KB Created: 2021-05-28 06:42:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 918ecc94c4ad5d0146728dbcfa8cf013 SHA-1: 296b9a0413b9562ca027be19af35353f058940ba SHA-256: a257707b81e83035adf9c3add2f46013f7434a84b6cc290146fc82fa55a367e7
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, suggesting a link farm designed to redirect users to malicious sites. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware distribution. The embedded URLs and the heuristic firings point towards a tactic of using a seemingly innocuous PDF to funnel users to further malicious content.

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.
  • 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://mezovuduw.ru/strik?utm_term=te+odio+como+nunca+quise+a+nadie+pdf+gratis+descargar PDF link annotation
    • https://mejuxubewa.weebly.com/uploads/1/3/4/0/134041058/2385683.pdfIn PDF document text
    • https://dojinutek.weebly.com/uploads/1/3/4/1/134108596/pemusodusa-vifal-tuzomivisag.pdfIn PDF document text
    • https://mazokozofifux.weebly.com/uploads/1/3/4/3/134305155/9297347.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4386621/normal_603d3c25aeaa9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4474446/normal_606b526db96d2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4494681/normal_6022f78850a24.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4487419/normal_5fc5bf70e5afd.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4456119/normal_5ffefb18c4d6f.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4375708/normal_60087dd8013b1.pdfIn PDF document text
    • https://farumurul.weebly.com/uploads/1/3/5/3/135326432/f9eaca909.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450635/normal_605d3bfcbbc62.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4410727/normal_5ff0b42095dfa.pdfIn PDF document text
    • https://xobagesimijuvu.weebly.com/uploads/1/3/0/7/130776740/fulutusowewokebovap.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4388612/normal_606873522fc34.pdfIn PDF document text
    • https://doxipawuno.weebly.com/uploads/1/3/2/6/132682924/rokupifetum.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/dc0efe6e-54ab-40a6-a7c7-7e2bf9ac6bfc/materiales_petreos_artificiales_ceramicos.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c42f5c2b-c6dc-478d-8166-9a10099335b7/what_is_the_second_warrior_cats_book.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4e653ec0-c57f-4def-92c8-2c882ba0f9e1/safivadeviwulibu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/de900271-897f-4e65-bbad-fb1d1b0eb005/54173330456.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f60ad8c0-1b68-4e39-895b-74daaf34fdc5/network_topology_slideshare.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b00c7708-c93e-4da8-95a0-b16ec0e81106/34448912270.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/34077271-3d27-43d1-abfa-c2a65608cd04/how_update_garmin_nuvi_free.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
    • https://savannah.gnu.org/projects/freefont/In PDF document text
    • http://www.gnu.org/licenses/In PDF document text
    • http://www.gnu.org/copyleft/gpl.htmlIn 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_off0000fbae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBAE 6440 bytes
SHA-256: edf517a561ed5132c6c1d5718ac6ff9d870a00e6f43a91762fd168a2279cca75
font_01_sfnt_off00010ba4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BA4 5520 bytes
SHA-256: 80000bf2da7ca2ca7c3c671d5c8611e4d4f834cf7f21d764c4f70a4d2e459df0
font_02_sfnt_off00011e45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E45 12728 bytes
SHA-256: efed387f0bed38c5bf7297df2005c6596748ad700c656603fb1faedc19f7f7b9