Malicious PDF — malware analysis report

Static analysis result for SHA-256 e4b13761ebe43336…

MALICIOUS

PDF

81.8 KB Created: 2021-08-16 08:05:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b375761ba8ecb710064e7adbdfa66d0e SHA-1: a45159c9be1fd8c30c3b22a54d7c49304f4f68a9 SHA-256: e4b13761ebe433362b06bd5e7faf97a88a906b81f659a934caa51d289c7f0c84
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It contains numerous links pointing to compromised CMS uploads and disposable hosting, characteristic of a link farm. The embedded URLs, such as 'https://irlanc.ru/uplcv?utm_term=get+followers+for+instagram+app+apk+download', suggest a lure to download potentially malicious content or engage in phishing activities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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
  • 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 https://irlanc.ru/uplcv?utm_term=get+followers+for+instagram+app+apk+download
    • http://wellogo.in/userfiles/file///93874630058.pdf
    • https://hamzakocakoglu.com/userfiles/file/kefodajufuto.pdf
    • http://eltdb.com/UserFiles/files/66717051252.pdf
    • https://tirthmobile.com/wp-content/plugins/super-forms/uploads/php/files/sou7ao9e09vkh6dhhrdnenvfkh/xejerof.pdf
    • http://geose.ru/userfiles/file/27533164692.pdf
    • http://istanbulballoons.com/ckfinder/userfiles/files/77930109829.pdf
    • http://am-assets.com/aom/magnolia/userfiles/file/94978822349.pdf
    • https://neavocats.com/wp-content/plugins/super-forms/uploads/php/files/547eeb3770148f512000c56d95c6c5fa/winixubitesarakosipefe.pdf
    • http://kimbuunguyen.com/uploads/userfiles/file/ziridewarupibarexetasom.pdf
    • https://menlopark.com/wysiwygfiles/file/43474907657.pdf
    • http://gugugroup.com/userfiles/bakope.pdf
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9abb863818---81072060100.pdf
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16075f28cdf482---75426030723.pdf
    • http://chinajnbt.com/images/upload/File/58816562662.pdf
    • https://vickers-electronics.co.uk/wp-content/plugins/super-forms/uploads/php/files/47d7d640727770581ef3385816cc6808/8118856562.pdf
    • http://healhumanity.foundation/userfiles/file/89735579909.pdf
    • https://majubesar.info/contents//files/25021822460.pdf
    • http://mega.kz/media/upload/files/88002346939.pdf
    • http://growlink.biz/userfiles/file/97620605189.pdf
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082d297a19f8---nudodorezefidofa.pdf
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b03f1e9b8bf---17299082204.pdf
    • https://promise-land.com/upload/file/tafezatigexov.pdf
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1606c953aa2eb2---nifazajoruduzezije.pdf
    • 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_off0000dbdd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDBDD 16792 bytes
font_01_sfnt_off0000f3ef.bin
3afb5f59e1d6b1e64990151f957fccd1b0cd33bf5d5d2c74cc4e5a948631cb3f
pdf-font-stream PDF embedded font (sfnt) at offset 0xF3EF 16632 bytes
font_02_sfnt_off00011efa.bin
20cfe62dd872245712cc0e7b7fdd2638f981c892724fdb0fa453578d11ea23a2
pdf-font-stream PDF embedded font (sfnt) at offset 0x11EFA 11056 bytes