Malicious PDF — malware analysis report

Static analysis result for SHA-256 b26a85f4f0f7e85c…

MALICIOUS

PDF

74.1 KB Created: 2021-06-25 22:26:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 318089c87313c573afc3e2f1710f1523 SHA-1: d2b657049d3007ac0a6e8225873d2680675cbc81 SHA-256: b26a85f4f0f7e85ca570cd0be124280c2b990611091bb1fe8b4050bb7bffb9d3
156 Risk Score

Malware Insights

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

This PDF 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 CMS upload directories, likely serving as a distribution point for further malicious content. The presence of multiple distinct hosts and the use of UTM parameters suggest an attempt to obscure the true origin and purpose of the links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

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 http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f036c242ee---74490252382.pdf
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607078c6c3180---4225648028.pdf
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc49b729be---31227635265.pdf
    • http://zpb-maciejewski.pl/upload/fck/file/denepoguwuzazetikujaxo.pdf
    • https://avantkart.com/wp-content/plugins/super-forms/uploads/php/files/du646aavbqvha1koj1pd86qkqo/wuxakorifazun.pdf
    • http://klefmarken.se/upload/file/68094304271.pdf
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2ac566f897---dawowowivesapefenujom.pdf
    • http://www.moteco.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16072e2340f8b2---17134113010.pdf
    • https://f1com.ge/wp-content/plugins/super-forms/uploads/php/files/43063d855900ef42fc6bef81103b5697/61930236649.pdf
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/e7617051b25f7da350ba5b514a9ff11f/xuxivuragul.pdf
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16084d285c1226---20582501963.pdf
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079ed1a5921d---758242974.pdf
    • http://mientrungpetrohotel.com/users/files/97422706229.pdf
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/abeff1fb241bc6bb35c4085053dbb366/porasepujasigep.pdf
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0a724d02a0---5762459458.pdf
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e26a1eefcd---71352242078.pdf
    • https://alexandrapanayotou.com/web/images/static/file/91214870391.pdf
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a32c8f3b2f---tezatitajosexube.pdf
    • https://homeaestheticsllc.com/wp-content/plugins/super-forms/uploads/php/files/afc038e61d36d00a9f3fdefe98be667b/zadixad.pdf
    • https://bandai-k.com/userfiles/file/13512051529.pdf
    • http://www.atrium-tuiles.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a33c4722e7c---20176504557.pdf
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/85d4fadfe59ef5e079f5d810733017d4/58379565889.pdf
    • https://bmw-zona.ru/uploads/file/36606920184.pdf
    • https://www.mixedclass.com.au/wp-content/plugins/super-forms/uploads/php/files/q81b35jafdds6n7dfh7t3h47e9/95817138567.pdf
    • http://www.wallisandemmanuel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096ffea7955f---gugus.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=new+practical+chinese+reader+vol+2+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_off0000bc51.bin
d16daf114262bdbd6cc9ca5e888e6dcaac071df32419815760b3be00f17d7391
pdf-font-stream PDF embedded font (sfnt) at offset 0xBC51 16600 bytes
font_01_sfnt_off0000e780.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE780 16792 bytes
font_02_sfnt_off0000ff97.bin
aecbbf8eb3451e0615424e86e74151ae4c1d1a77044150ec56fc85af279dad0f
pdf-font-stream PDF embedded font (sfnt) at offset 0xFF97 10968 bytes