Malicious PDF — malware analysis report

Static analysis result for SHA-256 f912b4a39fd951c6…

MALICIOUS

PDF

79.7 KB Created: 2021-09-23 21:50:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 35d43842ed53dcf3bcff185705d6d9da SHA-1: 4e1a9d7ae2b46f8227ab0a2ff583de8ecdd6feb5 SHA-256: f912b4a39fd951c6160767d3e187d0a9ad3067c2b01b20e6c12d98e10e258c61
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection for phishing. The embedded URL and link farm heuristics indicate a phishing attempt, specifically impersonating Norton and using a lure for 'safe free Robux' to likely harvest credentials. The document body is heavily obfuscated, but the presence of external URIs and the link farm analysis strongly suggest a phishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Brand-impersonation credential phishing lure high SE_BRAND_CREDENTIAL_PHISH
    Document impersonates a well-known consumer brand and uses account-security / verification language ('unusual activity', 'account on hold', 'verify your account') to steer the reader to a credential-harvesting link. Corroborated by: call-to-action link host does not match the impersonated brand: https://laborke.ru/uplcv?utm_term=safe+free+robux+sites.
  • 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://laborke.ru/uplcv?utm_term=safe+free+robux+sites PDF link annotation
    • http://sportschoolindex.nl/images/uploads/57130831754.pdfIn PDF document text
    • https://drnanemilk.com/tctt/sites/aaa/file/vavupofesuwez.pdfIn PDF document text
    • https://roadtoring.com/wp-content/plugins/super-forms/uploads/php/files/e0391db68f70ea2d17fd7a4a81d52ff1/55299598524.pdfIn PDF document text
    • https://lamaisonducoeur.ca/upload/editor/file/97426886982.pdfIn PDF document text
    • https://guptajimarriagebureau.com/userfiles/file/3201681027.pdfIn PDF document text
    • http://prestinoequitacion.com/imagenes/upload/files/laroxojoruje.pdfIn PDF document text
    • http://sjar-tech.com/uploadfile/file///2021090812495211.pdfIn PDF document text
    • http://aibrpjoaae2.specialty-match.com/upload/files/garejenojuvolowatevog.pdfIn PDF document text
    • https://farmaciasacoor.com/site/upload/file/73238420374.pdfIn PDF document text
    • http://heyumpnd.com/userfiles/file///wogoref.pdfIn PDF document text
    • https://mtmnetwork.net/uploadEditor/files/95143499973.pdfIn PDF document text
    • https://bedandbreakfastholten.nl/userfiles/file/dilopotela.pdfIn PDF document text
    • http://bezagsecurity.cz/userfiles/26737998649.pdfIn PDF document text
    • http://emailreceptionist.net/userfiles/file/balobisi.pdfIn PDF document text
    • https://vinniescustoms.com/userfiles/files/banezumizawe.pdfIn PDF document text
    • https://ville-saintleonard.fr/pdf/begadisitilezobaz.pdfIn PDF document text
    • http://younewstoday.com/task/userimages/file/rutovalenetexuxoxut.pdfIn PDF document text
    • https://sibservis.com/ckfinder/userfiles/files/96507993978.pdfIn PDF document text
    • https://obermeyer-modemarkt.de/upload/file/89643765412.pdfIn PDF document text
    • http://secretlove.ch/ckfinder/userfiles/files/72836447016.pdfIn PDF document text
    • https://lbk-ingatlan.hu/uploads/file/xozirusebipasamexibemuv.pdfIn PDF document text
    • https://www.tzounakos-insurance.gr/ckfinder/userfiles/files/82060592743.pdfIn PDF document text
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614278b2700c9---bulagitos.pdfIn PDF document text
    • https://stonebuild.bg/f/uploads/files/ruwubuzapedite.pdfIn PDF document text
    • http://cutyoursupport.com/userfiles/file/17981929914.pdfIn PDF document text
    • http://pobierzplik.pl/uploads/files/vebozofu.pdfIn PDF document text
    • http://tarnava.eu/user_images/file/gofax.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_off0000d5d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5D2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ede4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDE4 16704 bytes
SHA-256: 4ef046f82ead8e4ad684b4e23477ee5a3fe4031acd602d5189d3056785977c2c
font_02_sfnt_off00011924.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11924 10476 bytes
SHA-256: 76a7456c6e4506d5bbde5ef46ec5367c6ef69af8c3b6a0c40347e85e74326384