Malicious PDF — malware analysis report

Static analysis result for SHA-256 324988b1a238fc51…

MALICIOUS

PDF

80.2 KB Created: 2021-09-13 19:08:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 248877ed74f9cf3b7c2a6b361d77350e SHA-1: d6649023757b5f36a249468067e15f4df1aab043 SHA-256: 324988b1a238fc517aee0651ab22d88882da6bf533166fa0605f488770468853
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by ML classifiers and ClamAV as malicious, with heuristics indicating a malformed exploit stream and a link farm structure. The numerous embedded URLs, including one pointing to 'pistant.ru', suggest a phishing or malware distribution attempt. No scripts were extracted, but the PDF structure itself is indicative of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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://pistant.ru/uplcv?utm_term=best+survival+rpg+android PDF link annotation
    • http://www.como-grup.ro/fisiere/file/82391397179.pdfIn PDF document text
    • http://gpmpoolandspa.com/ckfinder/userfiles/files/wimisewopejuzazoragimeg.pdfIn PDF document text
    • https://tssch.in/tssch/application/admin/uploads/file/98991926911.pdfIn PDF document text
    • http://transporteslaplata.com/imagenes_web/file/kamamajovi.pdfIn PDF document text
    • http://tz5168.com/uploadfile/image/2021/09/02/file/20210902_181119_104.pdfIn PDF document text
    • https://bhiringisamsankalimandir.org/ckfinder/userfiles/files/43754122140.pdfIn PDF document text
    • http://flyingkirin.com/uploadfiles/file/061137079569.pdfIn PDF document text
    • https://ytdrive.com/CKEdit/upload/files/70823342602.pdfIn PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/161330d83382d9---gilavipuwevaferav.pdfIn PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/c28m8eajulufhsgme0cmnm6ldk/17034077956.pdfIn PDF document text
    • https://bocion.com/ckfinder/userfiles/files/30761431313.pdfIn PDF document text
    • https://sanagustin.cl/files/serigag.pdfIn PDF document text
    • http://www.anjhimayath.com/upload/file/55329612149.pdfIn PDF document text
    • http://struttur-arch.it/userfiles/files/55700225471.pdfIn PDF document text
    • http://xn--80aatg4aaaddkhfhbf3evf.xn--p1ai/ckfinder/userfiles/files/5275989985.pdfIn PDF document text
    • https://vinasimex.com/uploads/file/20222650638.pdfIn PDF document text
    • http://tageedesign.com/ssmpt/documents/file/robiva.pdfIn PDF document text
    • http://angelascanu.it/uploads/file/bejoxedurovafomajebisa.pdfIn PDF document text
    • http://samurairamenbar.com/uploads/files/63901943508.pdfIn PDF document text
    • https://shriramsteels.in/public/ckfinder/userfiles/files/rujufevemiretemapamafiz.pdfIn PDF document text
    • http://www.galiantsolutions.com/emailimages/file/turufuri.pdfIn PDF document text
    • http://www.otevrenysklep.cz/ckfinder/userfiles/files/zosozelerakaja.pdfIn PDF document text
    • https://b2cdemo.tickets.com/content/files/gazumogelib.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_off0000d5b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5B4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000edcb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDCB 10784 bytes
SHA-256: 44955321db9cb21347e887cc4a211b44d9fbb8c45edeae9c95c27ca30b0171a0
font_02_sfnt_off00010690.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10690 17192 bytes
SHA-256: 30586046042320f62b6171d2d6c6f50069375a3be1dd8540f6487ae97081cb07