Malicious PDF — malware analysis report

Static analysis result for SHA-256 98b7d596af883d02…

MALICIOUS

PDF

74.7 KB Created: 2021-09-25 23:49:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 22c612abb69de538e9f7b42890942d62 SHA-1: b2f325db05245fa27882db8de976f00578ae23d1 SHA-256: 98b7d596af883d02b50fa0d504d42a93d38b62a00fe953d845b21e57efbacd96
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. It contains numerous embedded URLs that form a link farm, many of which point to disposable hosting or compromised CMS uploads, suggesting a phishing or malware distribution scheme. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this. No scripts were extracted, and the document body was unreadable.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://queure.ru/uplcv?utm_term=beginner+new+english+file+pdf PDF link annotation
    • https://urology-andrology.com/userfiles/file/32878424580.pdfIn PDF document text
    • https://equinox-e.com/upload/files/xubulakesatixosideg.pdfIn PDF document text
    • https://portalbime.com/UploadedFiles/New/file/rubav.pdfIn PDF document text
    • http://annabarons.lv/files/files/gitebumemosemugusuwoto.pdfIn PDF document text
    • https://nieruchomosciprzetargi.pl/files/file/32863423013.pdfIn PDF document text
    • https://alley.52886.tw/uploads/files/bipazu.pdfIn PDF document text
    • https://lodoshosting.com/calisma2/files/uploads/35026185305.pdfIn PDF document text
    • http://ebslang.net/_UploadFile/Images/file/xifonujerazubimog.pdfIn PDF document text
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614d8a71a9e37---27308115233.pdfIn PDF document text
    • https://cantarefides.ro/admin/userfiles/file/29793668467.pdfIn PDF document text
    • http://rilta.net/userfiles/files/88538612835.pdfIn PDF document text
    • http://tid.vn/upload/files/niguwajodirufawunu.pdfIn PDF document text
    • http://7sate.com/filespath/files/20210907203656.pdfIn PDF document text
    • http://orourkelawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/lonikere.pdfIn PDF document text
    • http://dsagco.com/Upload/file/noberokalanililapoxe.pdfIn PDF document text
    • https://aldaserwis.pl/ckfinder/userfiles/files/41065426512.pdfIn PDF document text
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1614dfc73874f5---zazolozukazijutugilamu.pdfIn PDF document text
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/e888be8426bd0772fe1d79c6768309f9/jaxujej.pdfIn PDF document text
    • http://hankaebertova.cz/userfiles/file/86351913094.pdfIn PDF document text
    • http://rpsbchamber.org/editorData/file/zepugefegevonilev.pdfIn PDF document text
    • http://innovatepc.com/userfiles/file/86293712061.pdfIn PDF document text
    • https://ana-jsc.com/upload/files/zajivinarazesiburimas.pdfIn PDF document text
    • http://ip-malkov.ru/uploads/files/90546165132.pdfIn PDF document text
    • http://xn--80age2amlc.xn--80adxhks/pics/images/file/84587467969.pdfIn PDF document text
    • http://polipack.ru/content/file/tuwezomiponodisaluvuwokus.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_off0000bb4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB4D 10536 bytes
SHA-256: f573eb036d07b473e398a3762ec21c5c92959d4c6bc002ed75d02a0ac3bf257d
font_01_sfnt_off0000d2fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2FE 19392 bytes
SHA-256: 4aa7ed33eba53550485c2430ce520b579a946dd7ee028b2e1fae593d2baa1f5d
font_02_sfnt_off00010554.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10554 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1