Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac812b3d2bc9a663…

MALICIOUS

PDF

73.3 KB Created: 2021-09-27 13:15:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: f6bad048c9e372fe78d5217595d0be50 SHA-1: 193efea368d2a26cc83d68ee53553835d691de1a SHA-256: ac812b3d2bc9a663b6db8cdde741a8c7380ffd02e2bfab3f9ebf545d181775fe
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to various domains, many of which appear to be disposable or compromised hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of creating link farms on potentially untrusted domains, suggesting an attempt to redirect users to malicious content. No scripts were extracted, but the presence of multiple external URIs and the overall detection profile strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://synerhu.ru/uplcv?utm_term=messenger+110.0+apk PDF link annotation
    • https://airbays.com/userfiles/file/netolegusulusaxitafugatab.pdfIn PDF document text
    • https://cardolf.ro/files/95145209673.pdfIn PDF document text
    • http://xinchenfast.com/upload/file/pivalidokisulopijonu.pdfIn PDF document text
    • http://kukubara.com/zdjecia/file/sinagezefumisomoruxawewax.pdfIn PDF document text
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/1613bf4b3345c2---20009969460.pdfIn PDF document text
    • http://suvagcentr.ru/userfiles/files/napurosa.pdfIn PDF document text
    • http://www.dr.schure.net/ckfinder/userfiles/files/89135856641.pdfIn PDF document text
    • http://karat-dobremiasto.pl/userfiles/file/jowewonetosipirajevil.pdfIn PDF document text
    • http://seamacros.com/upload/file/gomujanajajofajeto.pdfIn PDF document text
    • http://fields-on-earth.com/images/blog/file/pabifosemulelab.pdfIn PDF document text
    • http://studiomarazzi.eu/userfiles/files/74702376880.pdfIn PDF document text
    • http://xn----7sbqwxdbhblh2h.xn--p1ai/data/file/15502321436.pdfIn PDF document text
    • http://barahi.com/assets/userfiles/files/lobod.pdfIn PDF document text
    • http://wych123.com/upload/files/54765952274.pdfIn PDF document text
    • http://ideal-site.ru/userfiles/file/34848216486.pdfIn PDF document text
    • http://lgassociates.in/uploads/roroxolukebufuluzabeg.pdfIn PDF document text
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/16139d9f90288a---96647614384.pdfIn PDF document text
    • http://loca-granderoue-montaletang.com/ckfinder/userfiles/files/sijazag.pdfIn PDF document text
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614792c35f405---59463442722.pdfIn PDF document text
    • https://www.sexualaufklaerung-schule.ch/ck/ckfinder/userfiles/files/89920758918.pdfIn PDF document text
    • https://newfrio.com/userfiles/files/piretizureras.pdfIn PDF document text
    • https://gonguyenkhoi.vn/upload/files/gewijojabaxokukumuxapud.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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bae9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBAE9 17640 bytes
SHA-256: e04c2e9fbe5c9350d1649cb7cf2aa28c3d6c59507f533cb302ba871d322213a9
font_01_sfnt_off0000e7cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7CB 10396 bytes
SHA-256: 46dd183720fdb209d5cb1ba3115accfd2812ecc0519a07bebb7a37014732f0b0
font_02_sfnt_off0000ff87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF87 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1