Malicious PDF — malware analysis report

Static analysis result for SHA-256 91a8cef4f05a96d4…

MALICIOUS

PDF

123.1 KB Created: 2021-07-14 04:30:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-18
MD5: 497030e2180c66627170d759eb4e864f SHA-1: 0251e1c4196412cd933b4d7ec047d87b200688bb SHA-256: 91a8cef4f05a96d43dbad3bed7000ee8c13d98117556cad4123f43b6300b1696
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple compromised or disposable hosting sites, likely for phishing or malware distribution. The presence of numerous unknown URLs, some hosted on compromised CMS upload directories, reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://medicinasolidale.org/wp-content/plugins/super-forms/uploads/php/files/2819b9f9ea20afc15748e47dea53b92a/30252318354.pdf In PDF document text
    • http://cathayred-csr.com/img-cathay/files/90464884517.pdfIn PDF document text
    • http://gulfcoolcontracting.com/uploads/userfiles/file/file/sasarabalopupadafo.pdfIn PDF document text
    • http://www.roosprommenschenckelfoundation.nl/ckfinder/files/files/kotebironaji.pdfIn PDF document text
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/9daf7c3b9e18486ae1a6454cb6072568/zafojogotonajom.pdfIn PDF document text
    • http://ccswcd.com/userfiles/file/dazimizazaz.pdfIn PDF document text
    • https://ckd-otto.com/contents//files/45815442987.pdfIn PDF document text
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c69658ebb67---xidawimifojikix.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160804c5d684e7---47014094276.pdfIn PDF document text
    • http://www.pattyn360.com/upload/forum/files/wirobowawogesokepigepafow.pdfIn PDF document text
    • https://ecef-groupe.com/wp-content/plugins/super-forms/uploads/php/files/688qfegkeec9lieuurruqrduf3/97269421224.pdfIn PDF document text
    • http://abnicum.com/files/file/mipefap.pdfIn PDF document text
    • https://candbco.com/ckfinder/userfiles/files/zikatoja.pdfIn PDF document text
    • http://kennedy-jackson.com/clients/f/f7/f78508644b517540cdb1549d93860f53/File/viranituz.pdfIn PDF document text
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/cbf0d8b41382f3f9165c24aacaf8e1c7/21043860100.pdfIn PDF document text
    • https://www.havanasalsa-dance-tours.com/wp-content/plugins/super-forms/uploads/php/files/d9c13e374c375ea3d19abd5a6d754d0f/31498155620.pdfIn PDF document text
    • https://sygimportaciones.com/wp-content/plugins/super-forms/uploads/php/files/7ae27mb1t9i4unslh9i2os72v0/xetorej.pdfIn PDF document text
    • https://bandai-k.com/userfiles/file/69720536218.pdfIn PDF document text
    • http://childhood-matters.com/clients/49507/File/ludajuvi.pdfIn PDF document text
    • http://melly-incendie.fr/img_db/vixebanalowik.pdfIn PDF document text
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/hflfv1h6t22nl4k51jhu9cn7ap/zawafubilonevapetav.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b42abcdf389---pujekevusimejerebo.pdfIn PDF document text
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bab2b6cd4c1---zoxisofuzifetowurilirog.pdfIn PDF document text
    • http://www.jobsincrete.gr/images/_user_na/file/78495243388.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=big+brother+season+20+full+episodes+free+onlinePDF 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_off00017aea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17AEA 18600 bytes
SHA-256: a2ba11aef06694575ea42f0959cdff01176f571453e693ee23e5f92c3a66bd66
font_01_sfnt_off0001ac1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1AC1A 11312 bytes
SHA-256: fe75f8fb071c874988d64028193299d7655e80467e28b2f779aa7fc9f9155f39
font_02_sfnt_off0001c64c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C64C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1