Malicious PDF — malware analysis report

Static analysis result for SHA-256 b40b30916f9831f2…

MALICIOUS

PDF

85.7 KB Created: 2021-07-05 18:54:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6aa75de1803c0b573c43e369b64f5da0 SHA-1: e7166989e43ae7f5455c14e255cce25c00a9cb9b SHA-256: b40b30916f9831f2d66da3b083a18dd44b4e5cdd783fef63be7dd4a8baa8da2b
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to phish users or lead them to malicious content. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf, suggesting the primary function is to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://tramtronbetong.com/uploads/userfiles/file/17207799446.pdf
    • https://perfecthospital.org/ckfinder/userfiles/files/rekobedub.pdf
    • https://mamproducciones.es/wp-content/plugins/formcraft/file-upload/server/content/files/1609292e8bbb03---83164798055.pdf
    • https://jgmurphy.com/wp-content/plugins/super-forms/uploads/php/files/3f6e7c4c660e403d0c9abf8f656c8a7c/52738783096.pdf
    • https://genegurumiraclehealer.com/userfiles/file/92541662762.pdf
    • http://airsoft1.ro/files/file/88595235569.pdf
    • https://mfdesign.hu/files/file/71218835434.pdf
    • https://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/160826b19bc8cc---35105618913.pdf
    • https://www.qbuildsoftware.com/wp-content/plugins/super-forms/uploads/php/files/055959436cfe5cc5941c79a918133979/vubodofa.pdf
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/160864dfa652bd---76953983058.pdf
    • http://osoboebludo.com/ckfinder/userfiles/files/xalexugemapasem.pdf
    • https://warungmimpishio.com/contents//files/ketoxokuj.pdf
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/oqp2r0jl5ijiid8j21arstio35/68737422121.pdf
    • http://associacaoguainumbi.org.br/wp/wp-content/plugins/formcraft/file-upload/server/content/files/160a2e0309cc24---sujoxalaxugareserefojes.pdf
    • http://studioturina.com/userfiles/files/pogepovajesiwakilodum.pdf
    • http://in-dapt.com/wp-content/plugins/formcraft/file-upload/server/content/files/160799f08d66ab---13887124504.pdf
    • https://argumentua.com/i/file/zurujupuvasevowi.pdf
    • https://alllegaltask.com/wp-content/plugins/super-forms/uploads/php/files/ug4bu941nb3a2ug3eeq7v6iaq1/29095089248.pdf
    • https://aulacvn.com/upload/fck/file/98498329261.pdf
    • https://bestmiamiturf.com/wp-content/plugins/super-forms/uploads/php/files/7edd35ba6972e191af2a95265e834cd0/tamenaki.pdf
    • https://www.blackandwhite-salon.com/wp-content/plugins/super-forms/uploads/php/files/fcda63a9b56eb2d77c2547fbfd06e8f5/4379227044.pdf
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a15701f557---19361617003.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=time+lapse+on+iphone+11
    • 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_off0000ee08.bin
363a8011d8ab56180fe7d0358da0c201c3e8e385ecff152df3229d3ad25f7832
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE08 17088 bytes
font_01_sfnt_off00011ab4.bin
47839d8d9c1a699cf4ebd67e6c578c083dbefd781acdf5753f3a0b51b7ecc7e8
pdf-font-stream PDF embedded font (sfnt) at offset 0x11AB4 10336 bytes
font_02_sfnt_off000131cd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x131CD 16792 bytes