Malicious PDF — malware analysis report

Static analysis result for SHA-256 71039a93aebeba9d…

MALICIOUS

PDF

77.6 KB Created: 2021-09-02 16:38:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 270a53f9e68459e8f0164d964e796128 SHA-1: a42238f3206ff740114474a9ea660faa5e38dd32 SHA-256: 71039a93aebeba9d17400bc7a5a548ec579857cf93319369e57794e7ab16f3a1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains a link farm pointing to compromised WordPress upload directories, suggesting it's used to distribute malicious content. The presence of numerous external URIs and the nature of the hosting indicate a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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.suffaheducation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a30afe97b86---2969720691.pdf In PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/td8omps489bm6fii56c9kg0au1/12533325758.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609a7a5cb0a0f---demokizumupenavafoko.pdfIn PDF document text
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/319947ee9a951afc23e7a8ecb2de5d51/ridalef.pdfIn PDF document text
    • https://handientu.vn/userfiles/file/87071734413.pdfIn PDF document text
    • http://fhhsclassof70.com/clients/4/42/42ce21dc30e429aa976ba070b22ccf93/File/ketilirejolufesapadeverok.pdfIn PDF document text
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/7f39add4a7972b9140eef55ece218cfc/33870098514.pdfIn PDF document text
    • https://sancarspune.com/wp-content/plugins/super-forms/uploads/php/files/c4439725efff85a5bcbefeda5a4e66bb/fozasuvad.pdfIn PDF document text
    • https://deltarents.com/upload/ckfinder/files/pasibolumoxevuwawegewe.pdfIn PDF document text
    • http://crackershrimp.com/file_media/file_image/file/51562185828.pdfIn PDF document text
    • http://componentcnc.hu/uploads/ckfinder/userfiles/files/54509338801.pdfIn PDF document text
    • https://cengilli.com/icerik_images/file/padevasupab.pdfIn PDF document text
    • http://falerisztika.hu/tmp/xiwudero.pdfIn PDF document text
    • http://esenkardeslerinsaat.com/resimlerfiles/4839701377.pdfIn PDF document text
    • https://alfa-pechati.ru/wp-content/plugins/super-forms/uploads/php/files/205e46247bfefa73ae01d51eee77ef1e/muvaxob.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1608007418b10d---zeterepivanovukasevex.pdfIn PDF document text
    • https://graffitipaintstudio.com/wp-content/plugins/super-forms/uploads/php/files/df1a5cfe511aef9f169f48350fd539da/xizoxazazuwaj.pdfIn PDF document text
    • https://hoangphatdanang.com/uploads/image/files/19077301360.pdfIn PDF document text
    • https://unique.global/wp-content/plugins/super-forms/uploads/php/files/8d6cf72e6e444b021ccf2a23006aff7a/ravoti.pdfIn PDF document text
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/fe4d6f2e429dfb135d8a2f368cfbc500/wexolowujifeg.pdfIn PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160984288256c6---63469447380.pdfIn PDF document text
    • http://a1-automotivegroup.com/upload/files/pifanoposopon.pdfIn PDF document text
    • http://stonebreaker.at/30030505728.pdfIn PDF document text
    • http://handbook.hu/upload/page/file/75504278332.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=veterinary+embryology+2nd+edition+pdfPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cb4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB4A 11016 bytes
SHA-256: bf0d2f3d5ddae41c94428c33e85d864bafb8377961d89b239f6a16ee39b79e86
font_01_sfnt_off0000e481.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE481 17172 bytes
SHA-256: 71b5236cf3597858468f395c1b0fe56e097ea8b12f61f0aad0e64d5da1bde0dd
font_02_sfnt_off000110e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110E6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1