Malicious PDF — malware analysis report

Static analysis result for SHA-256 73aa44b471965733…

MALICIOUS

PDF

81.1 KB Created: 2021-09-21 18:31:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: a73fb63f1248e7c4c9b898bd13381ef7 SHA-1: 11f570d595c452cdff0fc0a2300c3f9d0afbe346 SHA-256: 73aa44b471965733e6b8c0f592bbd38e6c4d080ab2b1c4463029889558c692ea
164 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to compromised WordPress uploads and disposable hosting sites. The presence of a 'download button' lure further suggests a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 7

  • 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 farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://cructi.ru/uplcv?utm_term=counter+side+ios PDF link annotation
    • http://fertilityupdates.com/userfiles/files/83729026985.pdfIn PDF document text
    • http://robertoantoniz.com/resources/original/file/68055184455.pdfIn PDF document text
    • http://an-ocn.ru/ckfinder/userfiles/files/gabuvuzimugomuzafuke.pdfIn PDF document text
    • http://www.jokilaaksonratsastajat.fi/file/53549382070.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613e8b6e143bc---pamebinem.pdfIn PDF document text
    • http://levakov132.ru/userfiles/file/7149116128.pdfIn PDF document text
    • http://russia-ex.com/images/blog/file/8091311734.pdfIn PDF document text
    • http://ooexperience.be/assets/Image/files/38952481007.pdfIn PDF document text
    • http://chiesamadremarsala.eu/userfiles/files/zaniwa.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/wonijiriludevoranatukepas.pdfIn PDF document text
    • http://tsnpharma.com/upload/files/vogugarumumoruratuwomak.pdfIn PDF document text
    • https://rowanmkt.com/Uploads/ckfinder/userfiles/files/jewef.pdfIn PDF document text
    • http://www.farmaciapenil.es/userfiles/files/14792497736.pdfIn PDF document text
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1613590fac5569---7060938217.pdfIn PDF document text
    • http://bienbao.net/uploads/files/tenutibamix.pdfIn PDF document text
    • https://fatheragneliti.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b96e1af075---tonapimusetedekivepilewu.pdfIn PDF document text
    • http://geojeoceanhotel.com/userfiles/file/20210918083723.pdfIn PDF document text
    • https://isabellepieman.com/userfiles/file/80321851603.pdfIn PDF document text
    • https://contemporaryteas.in/admin/uploads/file/64823890774.pdfIn PDF document text
    • http://trenermichal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16143447dc2407---monedusopoxozoguxulojori.pdfIn PDF document text
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/b9b3dae8f85b0f5a92a73bcd575299e6/milaxamotudobivubog.pdfIn PDF document text
    • http://kennyre.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139773a29b45---tovuvapas.pdfIn PDF document text
    • http://neoneophytou.com/ckfinder/userfiles/files/7113522480.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_off0000d736.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD736 10164 bytes
SHA-256: 3455e47c91f76dd066d34c4ee4bbafe992348c957b1e64d2452cdaa570b1549c
font_01_sfnt_off0000ee1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE1B 18624 bytes
SHA-256: ad3c2da75ef87e6c73e66486a3b6640a0192f421e2a81ebc77c96744d4d2d630
font_02_sfnt_off00011f63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F63 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1