Malicious PDF — malware analysis report

Static analysis result for SHA-256 fe79ceca3f7a2503…

MALICIOUS

PDF

82.1 KB Created: 2021-09-21 18:03:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: e0656e7709809b876fc68355e2c6da1a SHA-1: 381adef0d097142f5215a1986a20cfc7d2f341fd SHA-256: fe79ceca3f7a2503bc0d2c7d17d21a14ea68137f13b3a93fed1fe70ad0de532b
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous external links, many pointing to potentially compromised CMS upload directories, indicating a link farm or distribution mechanism. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the structure and URL patterns suggest an attempt to lure users to external resources, potentially for further exploitation or SEO abuse.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • 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.
  • 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://czdashan.cn/uploadfile/file/2021091522560273499.pdf In PDF document text
    • http://precisao.org/files/files/tajunonizujina.pdfIn PDF document text
    • http://detmers-kontejner.hr/files/62176988321.pdfIn PDF document text
    • http://davidhammerstein.org/ckfinder/userfiles/files/91992373619.pdfIn PDF document text
    • https://wtmasonry.com/ckfinder/userfiles/files/bijaxakemojafezo.pdfIn PDF document text
    • http://rrbrentacars.com/files/others/85261145315.pdfIn PDF document text
    • http://ventensis.lt/public/ckfinder/userfiles/files/42041984898.pdfIn PDF document text
    • http://minerva-collection.net/files/files/6579807419.pdfIn PDF document text
    • http://linker-apps.com/files/texomevenap.pdfIn PDF document text
    • https://svenjakretschmer.com/ckfinder/userfiles/files/wefoxix.pdfIn PDF document text
    • https://businesslife.com/content/file/85713112467.pdfIn PDF document text
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/30ac7ff5bbb68227b1fc590271c0ac8a/jezumutapafusiwegudezaro.pdfIn PDF document text
    • http://huabulaw.com/uploadpic/2021-9/file/2021091605154973499.pdfIn PDF document text
    • http://alde-pace.org/ckfinder/userfiles/files/41628260712.pdfIn PDF document text
    • https://akamercedes.com/images/uploads/files/11812294522.pdfIn PDF document text
    • https://congnghiepxd204.vn/upload/files/vatudodutemere.pdfIn PDF document text
    • https://timminsrenovations.ca/file/FMDdXtfs4EN7o9Nw.pdfIn PDF document text
    • https://davidfoleyinc.com/userfiles/file/kalawewidajod.pdfIn PDF document text
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16134fa6fe6208---fuzimumobasa.pdfIn PDF document text
    • http://jonellchem.com/upload/files/63604796168.pdfIn PDF document text
    • http://tano-cable.com/d/files/banoxarevimule.pdfIn PDF document text
    • https://majubesar.info/contents/files/ronogivopubogidopowuwutak.pdfIn PDF document text
    • http://okmarin.ru/userfiles/file/fodapasegizepelijog.pdfIn PDF document text
    • https://csom.cz/wp-content/plugins/super-forms/uploads/php/files/a91a54f7c7c912ab400ca2642a1b016d/24757764962.pdfIn PDF document text
    • http://konditsionery-zheleznodorozhnyi.ru/upload_picture/file/baxedugavifadidafebus.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=dirty+pokemon+rom+hacksPDF 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_off0000dc0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC0F 17596 bytes
SHA-256: 18348e6f09db40a9a3a10585ea0c236b57f6af6738cd89e01a085efd7e88b824
font_01_sfnt_off000109ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109AB 10800 bytes
SHA-256: 2e3ba41228b1c8b1576014db639e309c743c63654b68e85c3023626a8cee1b75
font_02_sfnt_off00012270.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12270 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1