Malicious PDF — malware analysis report

Static analysis result for SHA-256 a0c3f347b067a767…

MALICIOUS

PDF

75.8 KB Created: 2021-09-09 09:00:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: dcb3cbedebd7cf3214ff7dcf670e85f4 SHA-1: d63e51980c7889aa28af9753f12c22905d31b98a SHA-256: a0c3f347b067a767a1f98ed0ba8fcf47dd1ee025aa50d07b230c5028c0807b2e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to disposable hosting and are structured as link farms, a common tactic for phishing or distributing further malware. The presence of external URIs and the link farm heuristic strongly suggest an intent to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://crewmak.ru/uplcv?utm_term=how+to+lower+brightness+more+on+android PDF link annotation
    • http://hzxf.com/images/upload/File/tobafepa.pdfIn PDF document text
    • http://www.vljainandco.com/userfiles/files/disuzalebojezid.pdfIn PDF document text
    • http://ecosdaliberdade.com/ckfinder/userfiles/files/punuxadowejukolig.pdfIn PDF document text
    • http://kammatrans.com/userfiles/files/3856303668.pdfIn PDF document text
    • http://directopinion.biz/uploads/FCK_files/file/sudogikinoliw.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136bfc986cb2---65593019215.pdfIn PDF document text
    • http://bernardthevenet.fr/ckfinder/userfiles/files/duwunopiro.pdfIn PDF document text
    • https://venus-forever.com/image/files/kitetab.pdfIn PDF document text
    • http://www.juniorcollege.cl/ckfinder/userfiles/files/zoxibolim.pdfIn PDF document text
    • http://phuketdriveschool.com/userfiles/file/mikokexajimivavafoba.pdfIn PDF document text
    • http://coiffurenais.com/userfiles/file/sirab.pdfIn PDF document text
    • https://classoft.ro/userfiles/file/55591203128.pdfIn PDF document text
    • https://cosonnguyenthanh.vn/webroot/userfiles/files/bimaxopuvelikunaw.pdfIn PDF document text
    • http://vallovin.it/userfiles/files/11243577287.pdfIn PDF document text
    • https://mandarinusa.com/userfiles/file/1630456334.pdfIn PDF document text
    • https://cometgroupinternational.com/ckeditor/ckfinder/userfiles/files/44355691679.pdfIn PDF document text
    • http://cdmatik.com/uploads/file/fuzixudodosodik.pdfIn PDF document text
    • http://murasakijr.com/uploads/files/1503340399.pdfIn PDF document text
    • http://turinhotelcompany.com/userfiles/files/65100347847.pdfIn PDF document text
    • https://greenturtleproductions.com.au/wp-content/plugins/super-forms/uploads/php/files/ec5b84e407fef875101e709c0075dfaa/jiweb.pdfIn PDF document text
    • https://expomediainc.com/upload/file/melode.pdfIn PDF document text
    • http://prunay-en-yvelines.fr/ckfinder/userfiles/files/84911740942.pdfIn PDF document text
    • https://calienglish.com/ckfinder/images_store/files/xaraxasojotel.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_off0000c428.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC428 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dc3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC3F 10912 bytes
SHA-256: e313a7800aa4e8c2cd487780e041d7191ef847082fe0109972b2167da545de86
font_02_sfnt_off0000f518.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF518 17204 bytes
SHA-256: 087c06168fe9080f839d019740dba267ef2322b3ffd9b4cb29b199fd45a28292