Malicious PDF — malware analysis report

Static analysis result for SHA-256 5424873b06cdc76f…

MALICIOUS

PDF

77.0 KB Created: 2021-09-18 16:07:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 572f409e33b8360c2be272d586083708 SHA-1: f6b049c8c8c58153f6c45afc3e3e9a8ea1d6ee95 SHA-256: 5424873b06cdc76f4d186cefc906abd768d8f955e00dc0edc4d18aa378ee0385
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Static analysis revealed it functions as a link farm, containing numerous URLs pointing to various domains, some of which are hosted on compromised CMS upload directories. These links likely lead to phishing pages or malware downloads, consistent with a spearphishing attachment attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 https://infrive.ru/uplcv?utm_term=hay+adblock+para+android PDF link annotation
    • https://magnanelli.com/userfiles/file/53461526233.pdfIn PDF document text
    • http://musiclivemarsala.com/userfiles/files/tibokiresapu.pdfIn PDF document text
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613f9e87da253---80424359948.pdfIn PDF document text
    • http://savaksangida.com/resimler/files/1149029693.pdfIn PDF document text
    • https://www.bluegreenshouseboats.in/wp-content/plugins/formcraft/file-upload/server/content/files/161380c9d807d2---70255104506.pdfIn PDF document text
    • https://ruxthai-guesthouse-chiangmai.com/ckfinder/userfiles/files/61899924678.pdfIn PDF document text
    • http://vizit-k.net/uploads/editor/files/55128416020.pdfIn PDF document text
    • http://kalmi.ru/upfiles/files/tasoluf.pdfIn PDF document text
    • http://ciaooo.ru/uploades/userfiles/file/sutefakazivonifoxalapupo.pdfIn PDF document text
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613298a980f45---43184258004.pdfIn PDF document text
    • https://barrier.exma.cl/ckfinder/userfiles/files/69147359509.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/161315d2657017---talikibakumupe.pdfIn PDF document text
    • http://mindatpeace.us/uploads/files/88267918061.pdfIn PDF document text
    • https://dbmotorbrokers.com/userfiles/file/7922950458.pdfIn PDF document text
    • http://automyjka.pl/automyjka.pl/userfiles/file/zixilulijorabilazosewibij.pdfIn PDF document text
    • http://chinahongji.com/d/files/66035584126.pdfIn PDF document text
    • http://kargo-box.com/uploads/files/sanilebijofosimo.pdfIn PDF document text
    • http://camelliafb.com/uploads/files/202109092053439465.pdfIn PDF document text
    • http://begemot-rus.com/uploadfiles/file/2021090515351673499.pdfIn PDF document text
    • http://boxshop.mn/userfiles/files/78474305429.pdfIn PDF document text
    • https://rlmahtani.com/userfiles/files/5602607333.pdfIn PDF document text
    • http://pkynfe.net/userfiles/file/37871511879.pdfIn PDF document text
    • http://nhadatv.com/webroot/img/files/28092952962.pdfIn PDF document text
    • http://happyhanool.com/ckupload/files/14402132482.pdfIn PDF document text
    • 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_off0000cde0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDE0 10444 bytes
SHA-256: 926646a857fc862b618abcbead783acf0dbfd942996d6a2168e30322b8f810fa
font_01_sfnt_off0000e550.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE550 16004 bytes
SHA-256: 5c4c3a120ce04bdff0ff8ecb105e84aa7c59d75b3f7c39ecdc836bd65426f630
font_02_sfnt_off00010e8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E8F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1