Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f5ca0b135defbba…

MALICIOUS

PDF

151.0 KB Created: 2021-07-01 09:26:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b326e9a1d02bc6713efbd684a8fa24c1 SHA-1: 5a96c25a2a5fa7a28634ba0deaad0661a468a2ab SHA-256: 5f5ca0b135defbba44066d9fcc893a400a24b621cfe2ab1d592b0a91e6526b8b
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised websites hosting further PDF files. This suggests a multi-stage attack, likely for phishing or distributing additional malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9941

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://htfcompact.com/wp-content/plugins/super-forms/uploads/php/files/7d2c89b2d99e14c874535765fce1c0b2/zufuxelomaxewa.pdf
    • https://hrmconsulting.biz/upload/files/riwuwebudi.pdf
    • http://albertopizzetti.it/userfiles/files/faxapoxefutebirikusalu.pdf
    • http://www.adatechotomasyon.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b6c71ac498c---31778668408.pdf
    • https://promocionesnma.com/wp-content/plugins/super-forms/uploads/php/files/aed46081bbdf64f4e69855676d5daf31/pobexizuwejejer.pdf
    • https://alfa-pechati.ru/wp-content/plugins/super-forms/uploads/php/files/936ea25716e9e9d598d725c5d8846131/52276075125.pdf
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16091060410732---noxixavokut.pdf
    • https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160c5346f222bb---verolorirefesuloma.pdf
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a97b166f04c.pdf
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/16091e6efd70d6---38432587851.pdf
    • https://www.analfissur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d57f276697---zavoviburi.pdf
    • http://matstravel.ru/userfiles/file/91138570146.pdf
    • http://lhdrum.com/User_File/UpFile/file/20210701055845_NjcxODkxMTM2Mjc=.pdf
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b754c99d8f1---suzupamupozumamiw.pdf
    • https://www.karavanlakesfet.com/wp-content/plugins/super-forms/uploads/php/files/79c80b645bbba401055b89f0a837e4fe/62535915190.pdf
    • https://www.etbsupplies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc319235369---gafodosorubulenerojeguk.pdf
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae93b04e762---76316966968.pdf
    • http://abogarestudio.com/userfiles/file/38419941900.pdf
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609de5dac97e5---beraromoserapu.pdf
    • https://roweryelectra.eu/app/webroot/uploads/file/16240499914659.pdf
    • http://www.marcelasemper.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d984db9b01---namofe.pdf
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/o0k5gruhuv72lndq1nfrov5rg6/zikes.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=alexis+collins+cleary
    • 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_off0001ee81.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1EE81 16792 bytes
font_01_sfnt_off00020693.bin
3cba5d2a98229a623d3485658063cf278802b51374c700bfd7e8d497b9f2e0e6
pdf-font-stream PDF embedded font (sfnt) at offset 0x20693 18660 bytes
font_02_sfnt_off00023761.bin
e0a696f307da813561963671a94054f8f8cb68c043758f1292bc4fbbeed4be70
pdf-font-stream PDF embedded font (sfnt) at offset 0x23761 10324 bytes