Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b7eef1f3e893818…

MALICIOUS

PDF

74.5 KB Created: 2021-09-15 21:49:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 3154b7fd368c2afa6e70cc0e5afff348 SHA-1: 4a53a45c3da3e779a0ed0f74976ff62b0d2e19d7 SHA-256: 4b7eef1f3e893818c55cdc988d1d781f2c1b14d184f6a616acacadeb24a34a4f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external URLs, many of which are hosted on disposable domains, indicating a link farm designed to redirect users. The presence of embedded URLs and the nature of the heuristics suggest an attempt to lure users to malicious sites, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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 https://allytemp.ru/uplcv?utm_term=lord+of+spins PDF link annotation
    • http://kelakewangshangduchang.a9188.com/upload_files/art_files/files/20210902_231109.pdfIn PDF document text
    • http://speakingaboutnetworking.com/ckfinder/userfiles/files/vimizonemazudexedukarit.pdfIn PDF document text
    • https://z87992961.com/upload/files/20210909043529.pdfIn PDF document text
    • https://ceiling.holcom.vn/webroot/img/files/61410904829.pdfIn PDF document text
    • https://mygamedaysports.com/wp-content/plugins/super-forms/uploads/php/files/b1a2bc52d8cea4aec4e6233be96ea99f/29527257267.pdfIn PDF document text
    • http://pedraferro.com/files/files/83464296745.pdfIn PDF document text
    • https://aldwalia.com/userfiles/files/10423313695.pdfIn PDF document text
    • http://tindangnhadat.vn/upload/files/73176021355.pdfIn PDF document text
    • http://bifruit.mk/ckfinder/userfiles/files/puzisalizuginemewofuwiw.pdfIn PDF document text
    • http://cpviettin.com/upload/files/fapizubezomiwelok.pdfIn PDF document text
    • http://otworz-biuro-podrozy.pl/userfiles/file/kazope.pdfIn PDF document text
    • https://worldpigment.com/image/upload/File/29226044212.pdfIn PDF document text
    • http://crisismobile.com/ckfinder/userfiles/files/refizixerevamag.pdfIn PDF document text
    • http://sm.ac.th/ckfinder/userfiles/files/13732645661.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/tudalumabitelawibesobopel.pdfIn PDF document text
    • https://tedvandergulik.nl/userimages/file/jejid.pdfIn PDF document text
    • http://mxm-hosting.nl/img/editor/file/19054787895.pdfIn PDF document text
    • http://theemasternetworker.com/ckfinder/userfiles/files/pinozafo.pdfIn PDF document text
    • https://hw-power.com/uploads/ckfiles/files/6137dde4e0375.pdfIn PDF document text
    • http://circolonauticofavignana.it/userfiles/files/83217202502.pdfIn PDF document text
    • https://tcufroghouses.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613251febf4d2---59439849697.pdfIn PDF document text
    • http://brno-skoleni.cz/ckfinder/userfiles/files/66324914709.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_off0000c18e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC18E 17496 bytes
SHA-256: 693a045745575daae585427036daaf4fa647bfe6c9d48b319863907e48d2bb6c
font_01_sfnt_off0000ee3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE3C 10008 bytes
SHA-256: a8c3c8d0d18b8ad66e4f54c6a5abc3de8caac303c680f7385aa21f419faa1ab2
font_02_sfnt_off00010470.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10470 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1