Malicious PDF — malware analysis report

Static analysis result for SHA-256 623f585c06795bd9…

MALICIOUS

PDF

69.5 KB Created: 2021-09-28 21:24:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: d951a4e296732e5dff82cf23f2505050 SHA-1: 9dde39d041699d21184eb858ceff01e864b9c146 SHA-256: 623f585c06795bd96f9c46333a5b82e2f08398c6481b604443184a0f2096fba3
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous external URIs and is identified as a link farm on disposable hosting, suggesting a phishing or malware distribution scheme. Although no scripts were extracted, the presence of embedded URLs and the link farm heuristic strongly suggest the document's purpose is to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://synerhu.ru/uplcv?utm_term=apk+keyboard+2020 PDF link annotation
    • http://dulichtantai.com/files/uploaded/files/11504214554.pdfIn PDF document text
    • http://xn-----6kcaheblih5ab0a6afqbzoqe.xn--p1ai/ckfinder/userfiles/files/dinufeto.pdfIn PDF document text
    • http://homeloanz.net/images/e/file/60218844936.pdfIn PDF document text
    • https://cualuoihoanmy.com/uploads/userfiles/file/jipemafuniwita.pdfIn PDF document text
    • http://beastyenergy.com/userfiles/file/mebupinosizituwe.pdfIn PDF document text
    • http://sapientgenerator.ru/files/userfiles/files/zidopixebiribexak.pdfIn PDF document text
    • https://kabelkyaobuv.sk/editor_uploads/files/temoxazuvonefezipigevob.pdfIn PDF document text
    • https://refoca.cenacat.org/yiicms/ckfinder/userfiles/files/wubibederose.pdfIn PDF document text
    • http://artdental.hu/editor_up/gukegamomumobuwamivedamu.pdfIn PDF document text
    • https://unitjaya.com/contents/files/17402936888.pdfIn PDF document text
    • https://komunalno.vrgorac.hr/files/domumofifaluvub.pdfIn PDF document text
    • https://mannerfeltdesignteam.se/ckfinder/userfiles/files/53304886114.pdfIn PDF document text
    • https://gulfcans.com/home/madarmun/public_html/gulfcans/images/bulk_images/files/62513330335.pdfIn PDF document text
    • http://cartopack.be/Images/file/dagewitavumurutofik.pdfIn PDF document text
    • https://vantainoidia.vn/ci/userfiles/files/lukubuxigubamumu.pdfIn PDF document text
    • http://dailymaytrogiang.com/userfiles/files/nonapetepedo.pdfIn PDF document text
    • http://sspvjd.com/FileData/ckfinder/files/20210919_D4DB0D8138B0508C.pdfIn PDF document text
    • http://dichvu12h.net/userfiles/file/38339079641.pdfIn PDF document text
    • https://www.loscam.com/lib_common/ckeditor/ckfinder/userfiles/files/89235982849.pdfIn PDF document text
    • http://exosportsante.fr/ckfinder/userfiles/files/19209950152.pdfIn PDF document text
    • http://orvositudasbazis.eu/images/upload/file/4960663550.pdfIn PDF document text
    • https://areopag.ru/sites/default/files/uploads/domizewovapumamepalelix.pdfIn PDF document text
    • http://investgeorgia.ge/userfiles/file/53024474100.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_off0000b0a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0A1 15704 bytes
SHA-256: 43b730b02c9014900b326985e76eb6877ceb2f23f1ab50cf61652771a423554e
font_01_sfnt_off0000d8bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8BB 10448 bytes
SHA-256: 1b27265e03d2fa528798789a9877fa90cc823bafca462df463c4a5327e837c5b
font_02_sfnt_off0000f05d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF05D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1