Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c43028d4867ae1c…

MALICIOUS

PDF

90.6 KB Created: 2021-09-12 08:33:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-27
MD5: 4ec66750f556d912ebde2f5dd06c1194 SHA-1: 15395fdab10f646d9bae1628fa5426fe89ad5a50 SHA-256: 5c43028d4867ae1cef1d773a37694da51e900e950f2e2050a407c48a17150704
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple distinct hosts, with one URL identified as a disposable link farm. The document body is heavily obfuscated and unreadable, suggesting it is not intended for direct user interaction but rather to facilitate the redirection to external malicious resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

Heuristics 5

  • 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.
  • 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 http://napiarsaigh.com/images/88641868728.pdf In PDF document text
    • http://www.tiande-global.com/ckfinder/userfiles/files/zoweveginu.pdfIn PDF document text
    • https://flims.atelierleuthold.ch/userfiles/files/26553669434.pdfIn PDF document text
    • https://ibextrail.com/editor-images/53342343006.pdfIn PDF document text
    • http://market-oborudovanie.ru/upload/file/62415891558.pdfIn PDF document text
    • http://zakuskymoser.cz/www/ckfinder/userfiles/files/8792749105.pdfIn PDF document text
    • https://sanaspinler.net/calisma2/files/uploads/25813236911.pdfIn PDF document text
    • http://delfosventures.net/userfiles/files/75740470684.pdfIn PDF document text
    • http://transchem-tech.com/Uploadfiles/files/fewefakuxozegosedirilagex.pdfIn PDF document text
    • http://franceplus.fr/userfiles/file/koxesu.pdfIn PDF document text
    • https://allcreaturesinc.com/files/files/59618589113.pdfIn PDF document text
    • http://xn--ob0bjxt9h99icicrvkksa421cwwp7hiv4d6a.net/ckfinder/userfiles/files/velolukoxafifobakapa.pdfIn PDF document text
    • http://dulichtantai.com/files/uploaded/files/jojupozokipumi.pdfIn PDF document text
    • http://associatedreclaimed.reclaimedoils.com/userfiles/files/4711636818.pdfIn PDF document text
    • http://unionnutritech.com/upload/files/24665785660.pdfIn PDF document text
    • http://yuanhebiotech.com/upload/files/doranuworov.pdfIn PDF document text
    • https://wolfgang-photography.com/userfiles/files/nafitena.pdfIn PDF document text
    • http://reklamaopole.pl/userfiles/file/repobij.pdfIn PDF document text
    • https://pcparts.fr/ckfinder/userfiles/files/77083111963.pdfIn PDF document text
    • http://ms-beauty.com/ckfinder/userfiles/files/60335623477.pdfIn PDF document text
    • https://semot.com/Store/userfiles/file/venineripupenif.pdfIn PDF document text
    • http://aallergy.friend-match.com/upload/files/82968839328.pdfIn PDF document text
    • https://alzubidi.com/userfiles/files/viguwulakuloxafokif.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=secure+coding+in+c+and+c%2B%2B+2nd+edition+pdfPDF link annotation
    • 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_off0000f815.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF815 10876 bytes
SHA-256: 4598c09ec2ec7c252375357a728eed58358d97b3a8c3d66a87c45e8d73206116
font_01_sfnt_off00011133.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11133 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012945.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12945 19552 bytes
SHA-256: 21b934f320719f1c1ebb9bda50a71be25ac27b37acf12a777c6f44643581e472