Malicious PDF — malware analysis report

Static analysis result for SHA-256 135c2b48841ab08d…

MALICIOUS

PDF

80.1 KB Created: 2021-09-17 12:05:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3fa84fd41189a1c47c8d15d2ffe275ad SHA-1: e9a2035443ed4eb567d8acf255333b3969cb663d SHA-256: 135c2b48841ab08d17e1fe6015c9a5c0482bc930aecb18699ebea47cb9ac28e1
104 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and a significant number of external links, many pointing to compromised WordPress sites and disposable domains. These links appear to be part of a link farm designed to redirect users to download malicious files, likely exploiting a client execution vulnerability. The ML classifier strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 6

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://vico-real-estate.com/ckfinder/userfiles/files/sixudozotiva.pdf
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613249e1a3e20---salax.pdf
    • https://copacndg.com/images/uploads/files/99143356861.pdf
    • http://goldmustang.ru/files/files/muzakesupiseripopidezagax.pdf
    • https://cafeau1ait.xyz/js/ckfinder/userfiles/files/gazosukagovugufuvegu.pdf
    • https://cargobull.cz/res/file/97714965606.pdf
    • http://congluc.com/upload/files/36434351772.pdf
    • http://svadbavmoskve.com/content/xuploadimages/file/bavufolemelesukazeduva.pdf
    • http://floramarble.com/uploads/17688089769.pdf
    • https://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16140f41a7080a---10455119794.pdf
    • http://master-br.ru/img/file/bujaferiwugo.pdf
    • http://carmakers.cz/userfiles/files/burabedujadiz.pdf
    • http://haihengpharm.com/upload/files/66969609510.pdf
    • https://podimercrm.com/img/files/jamufufomokad.pdf
    • https://monographie.com/ckfinder/userfiles/files/madijapanikagu.pdf
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/qkqr36j6cf51dhs443dcfif3u1/4019089849.pdf
    • http://dr-onesrl.com/userfiles/files/tegodejo.pdf
    • http://justsayhi365.com/uploads/file/ziminunotijufewi.pdf
    • https://emons-verlag.com/testarea/cwsCMSlight/media/files/vofazogapes.pdf
    • http://miryangpension.com/FileData/ckfinder/files/20210914_9247A70E43881139.pdf
    • http://thuonghieutoancau.vn/uploads/files/posimotutotewawaniw.pdf
    • http://laser-piskovani.cz/democms/userfiles/file/xijidawevubefabarus.pdf
    • http://paykaaluminiya.ru/ckfinder/userfiles/files/84508389623.pdf
    • http://ckattorneys.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/gelenobovonez.pdf
    • http://serenetour.com/image/upload/File/girewo.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=videoder+beta+app+download
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d4e2.bin
9067d97c89cc59b8bf89ecde712c4381d0bc67873b750d9d2cc367c899936890
pdf-font-stream PDF embedded font (sfnt) at offset 0xD4E2 10412 bytes
font_01_sfnt_off0000ec5e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC5E 16792 bytes
font_02_sfnt_off00010470.bin
fc9ea3e078d52ceaba52bb06ad57c74eac91e48d6013dc7bc61c306c2856bf60
pdf-font-stream PDF embedded font (sfnt) at offset 0x10470 18072 bytes