Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5ff46a0bb2405b8…

MALICIOUS

PDF

86.3 KB Created: 2021-09-15 10:53:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: f8f1bc9bedfff98465d4ebc57e205c0d SHA-1: 04848cc3ae7d8cf0b420bb10fede5b7a414073f4 SHA-256: a5ff46a0bb2405b84f8c4396cd5247e224749e7968060b6f31b44120678c2033
156 Risk Score

Malware Insights

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

The PDF file contains a link farm directing users to multiple external URLs, some of which are hosted on compromised CMS platforms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is unreadable binary data, suggesting it's not intended for direct user consumption but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://kelsenator.com/userimages/78116768903.pdf In PDF document text
    • http://hsound.ro/images/custom/file/23878472802.pdfIn PDF document text
    • http://diencongnghiepvohoang.com/uploads/files/zeketokefuxewiletisa.pdfIn PDF document text
    • https://djecijagarderoba.me/userfiles/file/nitegosemegugifokovu.pdfIn PDF document text
    • http://cs-golfclub.com/ckupload/files/tovoden.pdfIn PDF document text
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/efcdb1b4ebc436d3a312b85417a6d1d5/5460627103.pdfIn PDF document text
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161350c7b187e1---87278947439.pdfIn PDF document text
    • https://beautifullifeuk.com/wp-content/plugins/super-forms/uploads/php/files/e7c0ddbdb4e97d1d8d43a6c6fe26b802/48715644806.pdfIn PDF document text
    • http://tourbusan.net/FileData/ckfinder/files/20210903_B233447EA22C4863.pdfIn PDF document text
    • https://publicbridge.pl/userfiles/file/betonigiporufix.pdfIn PDF document text
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133722f38650---44441034433.pdfIn PDF document text
    • http://www.asiacoservice.com/file/files/33125219415.pdfIn PDF document text
    • http://srcchaika.ru/files/uploads/files/42983667414.pdfIn PDF document text
    • http://agecarekorea.com/ckupload/files/maxufokajegol.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/44790133542.pdfIn PDF document text
    • https://sofanet.ro/ckfinder/userfiles/files/81477216265.pdfIn PDF document text
    • http://www.ks-klinika.ru/ckfinder/userfiles/files/rodonalepadujapawugusap.pdfIn PDF document text
    • http://decaiyun.com/upload/file/2109132004481829626xnbwgj84398.pdfIn PDF document text
    • https://pecintajp.com/contents/files/tidid.pdfIn PDF document text
    • https://ka-base.no/images_students/files/64600485293.pdfIn PDF document text
    • https://cahayaapi1.com/contents/files/13390278891.pdfIn PDF document text
    • https://ww150003.linebot.net/upfile/files/20210909191110.pdfIn PDF document text
    • http://birzebbugastpetersfc.com/files/file/xejet.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=roblox+arsenal+aimbot+mobilePDF 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_off0000ecb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECB7 10556 bytes
SHA-256: 8427627ddcd3996dbeab1a7a65d012f3f4704e135d67ec0e54c7eaf0fa581273
font_01_sfnt_off000104ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104CA 18068 bytes
SHA-256: 6b0a0840fa98444bde543777743871340839341b6372eff12600584978f8ed5a
font_02_sfnt_off0001339d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1339D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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