Malicious PDF — malware analysis report

Static analysis result for SHA-256 163b731dca9cdbce…

MALICIOUS

PDF

81.0 KB Created: 2021-09-17 21:43:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7c57eeea5a16bc1535e8aee72a487968 SHA-1: e0af4c288e818e4467bae31e77006d903f7662e4 SHA-256: 163b731dca9cdbce6e2a3e00bf33ed2be80cb41fca2837a41ba7859467599373
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to various domains, many of which are associated with compromised WordPress sites or disposable hosting, indicating a link farm designed to distribute malicious content. The 'SE_CALLBACK_LURE' heuristic suggests a phishing or tech-support scam pretext. ClamAV detection and ML classification strongly indicate malicious intent, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://smidgel.ru/uplcv?utm_term=phone+lags+when+typing
    • https://popcouncilinstitute.org/wp-content/plugins/super-forms/uploads/php/files/45d84d826ac743c3d5fef561dd744e68/20436296756.pdf
    • https://xn----7sbbg1ddpkdc.xn--j1amh/uploads/files/88715233781.pdf
    • http://dongtienlamnghiep.com/upload/file/79047094120.pdf
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/0nt92bus7h8t1etgn4v033j9b1/lewuvulajosupenodegusod.pdf
    • http://sinoorchids.com/image/file/xivinufiriza.pdf
    • https://chulintemple.org/CKEdit/upload/files/watewotapuwiladog.pdf
    • https://aymfly.com/aym_image/files/magisemun.pdf
    • https://lotteppta.com/beta/assets/file/xovalepidopuwasolanav.pdf
    • http://moveisgarciadigital.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612f6af68d30d---51433440346.pdf
    • http://thuephotocopytaihanoi.com/upload/files/80554260733.pdf
    • https://www.burnat-provins.ch/ck/ckfinder/userfiles/files/46913891325.pdf
    • http://joyerialaplaza.com/ckfinder/userfiles/files/nimobakuvasenemufoxumimo.pdf
    • http://eortak.com/img/fck_temp/file/48695828.pdf
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/14c9c09eccb1c4c890cfc1752f5a7635/533932150.pdf
    • http://sanarina.de/ckfinder/userfiles/files/zagoxonunokatov.pdf
    • http://hidropro.hu/upload/vizerasubaf.pdf
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/1ea51da4e9f5a42c427cae82f4f9aed4/razolidemuparixukinoluxo.pdf
    • http://sperrincaravans.com/images/file/79934900084.pdf
    • http://zangerlelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/mitipuwafuz.pdf
    • http://xn--3e0b556bhrbowi6undva.com/ckupload/files/taforegub.pdf
    • http://xn--38-mlcqjbufcz6h.xn--p1ai/userfiles/file/pudutujedima.pdf
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/1613864976e471---38746584182.pdf
    • http://ajisushionline.com/uploads/files/sezemosarim.pdf
    • http://nawooelcs.com/upload/userfiles/2021/09/files/210909022113.pdf
    • 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_off0000d7f4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD7F4 16792 bytes
font_01_sfnt_off0000f00b.bin
6cb5c05f6a81ee2d068ef7ffc6f00efdfe0f56e8a34a59a1811fd4eee2d71022
pdf-font-stream PDF embedded font (sfnt) at offset 0xF00B 10632 bytes
font_02_sfnt_off00010861.bin
c2c1e353565f3d186051999d57e9101fce0799508d75a2a94b4b30362cb65ece
pdf-font-stream PDF embedded font (sfnt) at offset 0x10861 17652 bytes