Malicious PDF — malware analysis report

Static analysis result for SHA-256 821d195b90e8e276…

MALICIOUS

PDF

95.0 KB Created: 2021-07-13 23:04:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 6a0d41e5cc7cf28b0696500038044ea2 SHA-1: ef5069f81300d65174c4030810ed473d963dc0bd SHA-256: 821d195b90e8e276421b3b3b4c67bf585e1a8cebb71fb8f58e9fba851d1ee3c5
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to compromised websites, identified by heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM'. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery. The document body is heavily obfuscated and unreadable, providing no direct content-based clues.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9918

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://coretry.ru/uplcv?utm_term=percy+jackson+and+the+lightning+thief+publication+date PDF link annotation
    • https://daaeportrett.no/upload/file/kowugosebajesogibubuv.pdfIn PDF document text
    • http://aristosaigonhotel.vn/uploads/files/ruzewepebewevugopa.pdfIn PDF document text
    • http://rethabise.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160971b109af4d---sefozilomefexuwe.pdfIn PDF document text
    • https://talaa-obour.com/webmisr/uploadwebmisr/file/3978880711.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/1608d938e4c0d3---61790525363.pdfIn PDF document text
    • http://sochi-polyana.com/ckfinder/userfiles/files/17712459899.pdfIn PDF document text
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609415355b727---7173221237.pdfIn PDF document text
    • https://mednet.mk/public_html/upload/userfiles/file/18480972256.pdfIn PDF document text
    • http://aggengr.com/uploads/CMS/file/vusewajo.pdfIn PDF document text
    • http://protok.pro/upload/files/12939978498.pdfIn PDF document text
    • http://swhwsolution.it/ckeditor-ckfinder-integration/uploads/files/7141173022.pdfIn PDF document text
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607504017de9c---sasobogetini.pdfIn PDF document text
    • http://hanleyresources.com/images/5350520523.pdfIn PDF document text
    • http://dragonspond.com/uploads/files/vizim.pdfIn PDF document text
    • https://topclassgreenery.nl/images/file/57535618081.pdfIn PDF document text
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/aa29ef4c4a0af735e760f565f94deec8/raxarug.pdfIn PDF document text
    • https://www.bluegreenshouseboats.in/wp-content/plugins/formcraft/file-upload/server/content/files/1608992cf439e8---88940277777.pdfIn PDF document text
    • http://carrasvilla.es/uploads/files/gafexipukatuw.pdfIn PDF document text
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/7odeqtpsvoomgbmn6o0c4bjqi2/54856100800.pdfIn PDF document text
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/1609409e9835a0---12965594477.pdfIn PDF document text
    • https://slezanie.eu/userfiles/file/66745929057.pdfIn PDF document text
    • http://osoboebludo.com/ckfinder/userfiles/files/23871416593.pdfIn PDF document text
    • http://bezagsecurity.cz/userfiles/vunibosepexobotef.pdfIn PDF document text
    • https://ngoctraithaibinhduong.com/uploads/news_file/xitima.pdfIn PDF document text
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000102d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102D7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011aee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AEE 11476 bytes
SHA-256: 5c783ab9903c4c6247760b5d27c236e562ab44e2472068ecb535a9229ef5d8f2
font_02_sfnt_off0001358d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1358D 1948 bytes
SHA-256: b033f7fcbcd390b2cb396fbb5f03ef01f7ca9afc151f9d9df21604321f961cfa
font_03_sfnt_off00013e8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E8C 17692 bytes
SHA-256: 5a7e01d978932f5c19b98c4b3ebce959b0f446eed2548401467fc33b2dfa9db2