Malicious PDF — malware analysis report

Static analysis result for SHA-256 f11f56bc572457cd…

MALICIOUS

PDF

83.4 KB Created: 2021-09-13 18:56:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9f19e8a53caa7d9e942885e2a88ddc52 SHA-1: 5cb36451fde94ddc5467bc1a3cf12b022f125f56 SHA-256: f11f56bc572457cd1f3e069bc4b9ad9be78d574ec130e1413f164e1266b3e93f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users to malicious content. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest it's part of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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 http://a2kat.ru/userfiles/file/9392213581.pdf
    • https://speak82.com/_UploadFile/Images/file/56661719338.pdf
    • https://nffcd.org/userfiles/files/70204990206.pdf
    • https://yar-net.ru/userfiles/file/kivuseridolikirujubuk.pdf
    • http://firmen-bekleidung.at/userfiles/file/rapesajutarorevixom.pdf
    • http://tehpromyar.ru/media/file/41818987555.pdf
    • http://powercleanperu.com/cms_powerclean_2015/sgi_userfiles/userfiles/files/pewaseparobanuredal.pdf
    • https://atlaskvartir.ua/data/uploads/files/30300051035.pdf
    • http://datcat.vn/2018/file/nalebivotex.pdf
    • http://getem.pl/files/file/kulilitemememidokuk.pdf
    • http://siltherm.com/ckfinder/userfiles/files/40883769464.pdf
    • https://negaratoto.com/contents/files/51147133329.pdf
    • http://hongphuc.vn/userfiles/file/xikiranikekod.pdf
    • http://vinmexindia.com/uploads/33925184088.pdf
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/2t336ofvqignku9j9au9755b27/wafinese.pdf
    • http://ecoaga.com/documentos/file/pepibiwonid.pdf
    • http://ncteonline.com/userfiles/file/nogimovafes.pdf
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/13b1804519cfc230bc0bbd1bd03ae60f/bigowadadazize.pdf
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/dt663v7p9pbqbf4acadt9tfkvr/tagonujofa.pdf
    • http://manu-transport.com/documents/file/pibigapefomupotujafib.pdf
    • https://pnp-studio.com/fckeditorfiles/file/21848665770.pdf
    • http://hypotekaprezamestnancov.sk/res/file/32715011956.pdf
    • https://saksisan.com/upload/ckfinder/files/puwuxokenebapej.pdf
    • https://imapcb.org/wp-content/plugins/super-forms/uploads/php/files/a281d01089cc940f2d241bb919fdfa7c/wunibebadadej.pdf
    • https://hoavily.com/uploads/files/82957240069.pdf
    • https://holcom-wd.com/webroot/img/files/lomijopufed.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=watch+harry+potter+with+subtitles
    • 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_off0000de67.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDE67 16792 bytes
font_01_sfnt_off0000f67e.bin
57fda2ff6e8a10928ec49be49b0fe7873a241a6c32d7c930bcf921ce51d4b94d
pdf-font-stream PDF embedded font (sfnt) at offset 0xF67E 10800 bytes
font_02_sfnt_off00010f68.bin
f712f45d800b935cb5c14b1f05f7a9ee4e2573b9414aeb9add08717c51089fb7
pdf-font-stream PDF embedded font (sfnt) at offset 0x10F68 18712 bytes