Malicious PDF — malware analysis report

Static analysis result for SHA-256 877a7c967a2ef8ce…

MALICIOUS

PDF

96.8 KB Created: 2021-09-18 19:36:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 525b053f55962e645491e43f5bccd1b1 SHA-1: a0e904736d32de5a8362e21db0dd3e9938ff3d3a SHA-256: 877a7c967a2ef8ce79561abedb33562240a2f66945a3427b463ee0dd6b09356f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which are hosted on disposable domains, indicating a link farm designed to redirect users. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests a malicious intent to distribute content or phish credentials through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9969

Heuristics 5

  • 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 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://medvor.ru/uplcv?utm_term=downloading+android+apps+to+sd+card PDF link annotation
    • https://m-astar.com/UserFiles/files/41295103595.pdfIn PDF document text
    • https://gymlesgeants.com/upload/editor/file/38495922500.pdfIn PDF document text
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614127c54e416---15468647166.pdfIn PDF document text
    • https://hirurgija.me/files/famovuwaba.pdfIn PDF document text
    • http://dreamcatcherltd.com/userfiles/file/rebizukofosafimewo.pdfIn PDF document text
    • https://mysilo.com/upload/ckfinder/files/zufomomodabisunelak.pdfIn PDF document text
    • http://thetestmag.com/userfiles/files/padixomasonudujadoki.pdfIn PDF document text
    • http://qcfloor.com/userfiles/file/41417876651.pdfIn PDF document text
    • http://uro-medical.pl/zdjecia/fotki/file/33232633473.pdfIn PDF document text
    • http://whkmradio.com/userfiles/file/fumisokedu.pdfIn PDF document text
    • https://www.baust.edu.bd/app/webroot/ckfinder/userfiles/files/xefozapisivivarase.pdfIn PDF document text
    • http://charolais-hessen.de/write/userfiles/file/rajepunefupujige.pdfIn PDF document text
    • https://www.verimevzabavu.cz/ckfinder/userfiles/files/fitemenuzaxiwawozular.pdfIn PDF document text
    • http://immodraft.de/images/architekten_agentur_images_/file/61360513061.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e4bc5ec9c9---lunipejowiraji.pdfIn PDF document text
    • https://www.piramideidiomas.com/ckfinder/userfiles/files/pobapetowamo.pdfIn PDF document text
    • http://chandravanshi.com/userfiles/file/pogosa.pdfIn PDF document text
    • https://derechosenred.org/aym_image/files/pexidagilirifor.pdfIn PDF document text
    • http://rafaelstore.ru/upload/files/sapepadamoriwavafujorune.pdfIn PDF document text
    • http://hophungvietnam.com/app/webroot/uploads/files/romuzawif.pdfIn PDF document text
    • https://egc.ecrom.work/syo/files/8531314494.pdfIn PDF document text
    • https://istanajp.com/contents/files/15259788983.pdfIn PDF document text
    • http://gazduire-domeniu.com/UserFiles/file/68714210642.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_off00011472.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11472 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012c89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C89 10644 bytes
SHA-256: 63e4d2effab168e47e1b077b29ab0b1cbc26792a24b370bceceeaf4a18d2095e
font_02_sfnt_off000144da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x144DA 18600 bytes
SHA-256: 5aef65d5396b2bd4ad4e8a7a9a388216817c59faf2d4af09b2aca1da8b3ae1ae