Malicious PDF — malware analysis report

Static analysis result for SHA-256 79c873ae98a3cb86…

MALICIOUS

PDF

75.4 KB Created: 2021-09-09 09:03:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 7fbbc367c20afc903ce64dd0d497657d SHA-1: 2ed560b44d39e0b80ad554cdaf4f47dfcffe9dc5 SHA-256: 79c873ae98a3cb8654fe05892a0c0a184357647e4c26fda466752858fdb13470
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains a high number of external links, many pointing to potentially disposable domains, suggesting a link farm or phishing attempt. The PDF_RANDOM_URL_LINK heuristic specifically flags a link to 'http://ambulatorioveterinariopisillibertozzi.eu/userfiles/files/fomakebetezemufirez.pdf', indicating a likely malicious redirection. No scripts were extracted, but the structure and numerous URLs point towards a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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
  • 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 http://zehanbiopharma.com/upload/files/rupejozuxejesapuvodugoba.pdf In PDF document text
    • http://grupposcorcia.it/userfiles/files/50423340758.pdfIn PDF document text
    • http://geobigoni.it/userfiles/files/69976382598.pdfIn PDF document text
    • http://ambulatorioveterinariopisillibertozzi.eu/userfiles/files/fomakebetezemufirez.pdfIn PDF document text
    • http://geoman.cz/data/file/15134765804.pdfIn PDF document text
    • https://istanajpdua.com/contents/files/12131810771.pdfIn PDF document text
    • http://starroadchina.com/userfiles/file/79652871007.pdfIn PDF document text
    • https://kaptenhoki.org/contents/files/16366136724.pdfIn PDF document text
    • https://elpollopaulino.com/cenavarra_userfiles/files/jepabelini.pdfIn PDF document text
    • http://nhadatv.com/webroot/img/files/marusobudinatabija.pdfIn PDF document text
    • http://dieukhactransam.com/uploads/files/64774226940.pdfIn PDF document text
    • https://nhahangthanghuong.com/uploads/files/19076991922.pdfIn PDF document text
    • http://www.pattyn360.com/upload/forum/files/72326966816.pdfIn PDF document text
    • http://aadcnfgl.netsociality.com/upload/files/kiwelegekuj.pdfIn PDF document text
    • https://falconshipping-uae.com/userfiles/files/42642303980.pdfIn PDF document text
    • http://fsgzb.com/upfolder/e/files/20210908105750.pdfIn PDF document text
    • http://adhdesign.de/userContent/files/20210903134618-wutajefojeletasepajage.pdfIn PDF document text
    • http://weldingplaza.com/files/file/20681890252.pdfIn PDF document text
    • http://objets.immoweiss.lu/userfiles/files/26837756182.pdfIn PDF document text
    • https://valserve.in/web/k/main_admin/ckfinder/userfiles/files/95264583886.pdfIn PDF document text
    • http://alphasigmaoverseas.com/userfiles/file/31145404698.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135ef82d5bbd---ganatejesawa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=streaming+desire+2011PDF 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_off0000bf58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF58 17780 bytes
SHA-256: 3e9d5131c18eb15c0cc8415b0c8ad66c2795ae6f2a68bdf07be40fcf7531d91c
font_01_sfnt_off0000edf8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDF8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001060f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1060F 10796 bytes
SHA-256: ab5a3a9e1fe4bb87fdfdb01df29b0c667362e679fcd89b99ec3490be37b0960d