Malicious PDF — malware analysis report

Static analysis result for SHA-256 9a213d9ac5d33c32…

MALICIOUS

PDF

81.1 KB Created: 2021-09-14 03:21:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b8a7ff8e079133f4b8282459bb1f9a86 SHA-1: c1863d396f174cbda3bb35e7d7022e7727cf4803 SHA-256: 9a213d9ac5d33c32bad721a8d249256e76eccb67e1f499da97b27f6953c8daca
172 Risk Score

Malware Insights

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

The sample contains embedded JavaScript, indicative of malicious intent. It also features numerous external URIs, including links to compromised CMS uploads and disposable hosting, suggesting a phishing or malware distribution scheme. The presence of a 'download button' heuristic further supports the attack pattern of luring users to download a payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 8

  • 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.
  • 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://coretry.ru/uplcv?utm_term=modded+among+us+android+free
    • https://minhkygroup.com/luutru/files/56265471209.pdf
    • https://egf.tw/test2/images/file/77670352357.pdf
    • http://kccmaul.com/files/files/lulebora.pdf
    • http://pensjonatagat.pl/userfiles/file/39505444950.pdf
    • http://studiofantino.it/userfiles/files/kurexafowof.pdf
    • http://cetis156.neutronds.com/assets/js/ckfinder/userfiles/files/24181020141.pdf
    • http://www.supair-lux.hu/ckfinder/userfiles/files/56831837042.pdf
    • http://johnmarzillier.com/ckfinder/userfiles/files/dafibobasofejuvo.pdf
    • http://rowerowaszkola.pl/imgturysta/files/wowipevaz.pdf
    • https://namdolove.com/FileData/ckfinder/files/20210914_A5A668CD369812E7.pdf
    • http://headrepublic.pl/images/files/38510286962.pdf
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1612f2aeab5ffc---6483760061.pdf
    • http://tunesistudio.eu/userfiles/files/27477572592.pdf
    • https://vsevolozhsk.mebel18.com/uploads/files/26772376747.pdf
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/tb1c6nnvoj97rnrnsgo4binh37/72312827763.pdf
    • http://azstorestudio.com/uploads/files/tixaw.pdf
    • https://hopclickhospitality.com/scgtest/team-explore/uploads/files/judumufivodabipuwepupo.pdf
    • http://maezawa-jidousha.com/js/upload/files/97926605207.pdf
    • http://sualpturizm.com/userfiles/file/rafasusukapumeva.pdf
    • https://www.breastcancerfoundation.in/wp-content/plugins/super-forms/uploads/php/files/adc04eca3de5eee3d6783ab832121c70/65620674711.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_off0000d893.bin
5806728ee70c03e755aacf81789e42b4ba34dabf23fca829aaa15ed23d8ab8f0
pdf-font-stream PDF embedded font (sfnt) at offset 0xD893 10644 bytes
font_01_sfnt_off0000f0a9.bin
0db31d4e4e3e43d17106495e8d5250d38ca26967d6ad10ce8a6e8a975ac5ed41
pdf-font-stream PDF embedded font (sfnt) at offset 0xF0A9 18080 bytes
font_02_sfnt_off00011f71.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11F71 16792 bytes