Malicious PDF — malware analysis report

Static analysis result for SHA-256 82e71c3eb184db4b…

MALICIOUS

PDF

78.3 KB Created: 2021-09-08 18:19:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: b9ac31eb1277c610940f8fe5f54337cd SHA-1: 52f81c02ed33b14374a6a245d864260468231514 SHA-256: 82e71c3eb184db4bb501aabe750dbed5db8ebdea7b36f20deb20a648d9e97221
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as a malicious PDF by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript and numerous external URIs, suggesting it is designed to redirect users to potentially harmful websites. The PDF's structure and the presence of external links point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://chcial.ru/uplcv?utm_term=grammar+worksheet+third+conditional+pdf PDF link annotation
    • http://anadolumatbaa42.com/genelresimler/file/2617539232.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fd641c7687---xonukaxet.pdfIn PDF document text
    • http://lussoleathertiles.com/test4/EDITOR/example/v2/userfiles/file/47509012229.pdfIn PDF document text
    • https://smartcrm.cloud/upload/files/wugigadudonenuxetobupubam.pdfIn PDF document text
    • https://skywaynepal.com/userfiles/file/pasovukabufodunubumiditul.pdfIn PDF document text
    • http://satunatc.ac.th/ckfinder/userfiles/files/55758694275.pdfIn PDF document text
    • http://foto-recepty.sk/images/fotky/pajotefubasoziga.pdfIn PDF document text
    • http://gok-maciejowice.pl/js/ckfinder/userfiles/files/sigajifuloveketafadul.pdfIn PDF document text
    • http://agroanaliz.by/upload/editor/files/87167266036.pdfIn PDF document text
    • http://woodwork.pl/ubezpiecz/obrazy/file/89085923690.pdfIn PDF document text
    • http://ckudzcssffhhj.handysociality.com/upload/files/maruvojedixiwoliluguwek.pdfIn PDF document text
    • https://pieseautocomenzi.ro/userfiles/file/jodijuwogemi.pdfIn PDF document text
    • https://sensesgrouphk.com/louis/STARKGROUP/ckfinder/userfiles/files/jivarapofegilox.pdfIn PDF document text
    • https://stef-nancy.fr/upload/document/fowizoz.pdfIn PDF document text
    • http://closehorses.com/userfiles/file/tevuzovomito.pdfIn PDF document text
    • http://sjzhtchem.com/upload/files/34999721028.pdfIn PDF document text
    • http://sirindhorn.net/upload/File/waxowevezisogegepemuti.pdfIn PDF document text
    • https://cortemadera.com/wysiwygfiles/file/62269197800.pdfIn PDF document text
    • https://cobaltinc.org/userfiles/file/10848132938.pdfIn PDF document text
    • http://suranareecommand.net/UserFiles/File/zasefabirexexiwut.pdfIn PDF document text
    • https://tpijobportal.com/ckeditor/ckfinder/userfiles/files/32961153348.pdfIn PDF document text
    • http://sieuthibongda.net/ckfinder/userfiles/files/vijepazijuzis.pdfIn PDF document text
    • http://goldmustang.com/files/files/likijavigunewino.pdfIn PDF document text
    • http://frankifoto.com/uploads/pages/files/tedodurabufaz.pdfIn PDF document text
    • http://delve-cr.com/uploads/50767253853.pdfIn PDF document text
    • http://www.slenderclub.cz/ckfinder/userfiles/files/83728497270.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_off0000cc74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC74 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e48b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE48B 11104 bytes
SHA-256: ab8fd5ae55fa268ab3988887813ce6a4d842d7695049a5b80a31905373489dc5
font_02_sfnt_off0000fe56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE56 17480 bytes
SHA-256: 7e0ac1be0498443e64f2aa4fc21691b25acc7e6d800a9ebcc732c5f95a0c8b7e