Malicious PDF — malware analysis report

Static analysis result for SHA-256 14a8c155e3441767…

MALICIOUS

PDF

126.7 KB Created: 2021-10-10 13:51:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 26a9714a12dfe094ebc0b4e456696699 SHA-1: e2b4dee3a8bd71ec741c6c6e4a071fae0883b1e5 SHA-256: 14a8c155e34417676312c3687eca315c85cfd3f55b31ee441bbcd131cfea0aa5
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it contains links to algorithmically-generated URLs and functions as a link farm on disposable hosting. The PDF contains embedded URIs that point to external resources, suggesting an attempt to redirect the user to malicious sites for phishing or further payload delivery. No scripts were extracted, but the presence of multiple external links is a strong indicator of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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=from+3+onwards PDF link annotation
    • http://www.gabrielamaciel.net/images/content/file/60771486048.pdfIn PDF document text
    • http://yalcinsezer.com/upload/ckfinder/files/foxorezor.pdfIn PDF document text
    • http://winhazel.com/indigo/ckfinder/userfiles/files/denemaxefotesomiwokadevut.pdfIn PDF document text
    • http://lucidareemantenerepavimentifaidate.it/userfiles/files/7427232088.pdfIn PDF document text
    • http://circolosilverblufitnessclub.eu/userfiles/files/21853793749.pdfIn PDF document text
    • http://tokstar.com/_UploadFile/Images/file/99963472046.pdfIn PDF document text
    • http://sasnowosielski.com/ckfinder/userfiles/files/jepinefabitos.pdfIn PDF document text
    • https://vipbeachhouse.com/uploads/editor/file/16124117892.pdfIn PDF document text
    • http://shinyoungvalve.com/userData/board/file/33444256387.pdfIn PDF document text
    • https://ddmmaze.altruistictech.org/documents/img/upload/files/wadagak.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/161543d3d5f918---25304276275.pdfIn PDF document text
    • http://cathyknightwaite.com/ckfinder/userfiles/files/78980271715.pdfIn PDF document text
    • http://neurooperations.com/ckfinder/userfiles/files/51933338500.pdfIn PDF document text
    • http://revucue.com/ckfinder/userfiles/files/75266991456.pdfIn PDF document text
    • http://runnersavezzano.it/public/userfiles/file/remuzanijofatisuzedek.pdfIn PDF document text
    • http://www.rannatennis.ee/data/upfiles/files/nirotexep.pdfIn PDF document text
    • https://onthespothousing.com/userfiles/file/gatafulirekogegumojog.pdfIn PDF document text
    • https://ritascreation.com/userfiles/file/besabizewixalufa.pdfIn PDF document text
    • https://kpii3yaw3-7nc.com/contents/files/bafedemulawitefutili.pdfIn PDF document text
    • http://laptopcuhaiphong.vn/upload/files/gepojimesele.pdfIn PDF document text
    • https://ymy-tea.tw/upload/files/lilep.pdfIn PDF document text
    • https://arhometutor.com/userfiles/file/95162501742.pdfIn PDF document text
    • http://fnathservices.com/upload/file/fopukavifubodu.pdfIn PDF document text
    • https://mediaget.com/userfiles/files/rapazatugetizokusuvesevo.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_off00018665.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18665 21324 bytes
SHA-256: 6a90f1555737c8f912f399c72d33b82a6edfbe21f8262c1cfaa0b9e8267aa459
font_01_sfnt_off0001bd7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1BD7A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001d591.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1D591 10276 bytes
SHA-256: b7b800e2f02c7c88f27e4059f25e4797f68094b40c34bd5deda00c83224e4f76