Malicious PDF — malware analysis report

Static analysis result for SHA-256 72fd7c4cff73f55c…

MALICIOUS

PDF

82.0 KB Created: 2021-09-17 23:18:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7a70c93df3d505cd5a48b58c9e0263ef SHA-1: e7fb66dd8bd9d7f889bf466ca1e68476244ae4bd SHA-256: 72fd7c4cff73f55ced5204a971af184bb33ae96f7877dbc7b149464cbb0252ca
172 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file is identified as malicious by ClamAV and an ML classifier, with heuristics indicating embedded JavaScript and a link farm pointing to compromised or disposable hosting. The presence of numerous external URIs, including one hosted on a compromised WordPress upload directory, suggests the document is designed to lure users into clicking malicious links or downloading further payloads. The embedded JavaScript, while not explicitly detailed, is a common vector for exploitation in PDF documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 8

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://queure.ru/uplcv?utm_term=present+simple+present+continuous+exercises+printable
    • http://xn--2-140-swe8h.xn--p1ai/files/3924129607.pdf
    • http://indagosrl.it/userfiles/files/6564555319.pdf
    • https://elperrocallejero.info/ckfinder/files/xajeresenog.pdf
    • https://vyaspublicschool.com/ckfinder/userfiles/files/9500087673.pdf
    • http://rigdrilling.org/userfiles/file/zejetonowosinokafuju.pdf
    • http://goforthegreengolfpools.com/userfiles/file/xelirazevevelixasux.pdf
    • http://pegastelco.com/pictures/files/54432846648.pdf
    • https://octvads.site/js/ckfinder/userfiles/files/79872309675.pdf
    • http://stsmcc.org/www/js/ckfinder/userfiles/files/sejutel.pdf
    • http://geomanteia.com/userfiles/files/64251944056.pdf
    • http://bwemfjhjk.friend-match.com/upload/files/88845721035.pdf
    • http://manu-transport.com/documents/file/rorenojawanipapewusazizu.pdf
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/161409e08f3fe8---kebojinepejedukore.pdf
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/ctg01mjs3iijvl6mgqc51mgi46/68611290186.pdf
    • https://cecprint.com/images/file/46946421654.pdf
    • http://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614218e6305d3---44816304895.pdf
    • http://modnyi-buket.ru/uploads/files/72844901553.pdf
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/1613037144161e---xojoro.pdf
    • http://jrecchina.com/ckeditor/ckfinder/userfiles/files/noximezerob.pdf
    • http://hunicorn.hu/userfiles/file/21155212273.pdf
    • http://badaranquehablar.com/userfiles/files/zofuxoxawexikaxetovozipip.pdf
    • http://sswjeans.com/files/purodadaren.pdf
    • https://andrejc.si/files/file/mefonowik.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_off0000dac3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDAC3 16792 bytes
font_01_sfnt_off0000f2da.bin
25be321ef78c35c496d1e318fdaf3c83cc508aaf46897add3ac19c32b31de779
pdf-font-stream PDF embedded font (sfnt) at offset 0xF2DA 10880 bytes
font_02_sfnt_off00010bcf.bin
e7c68715da8ce51760e1b62536605758db2b97631b0bfc7e7da5d9effff6b057
pdf-font-stream PDF embedded font (sfnt) at offset 0x10BCF 17784 bytes