Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ad178efca809ae2…

MALICIOUS

PDF

85.2 KB Created: 2021-09-07 10:53:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: b994f070728d92a10b45a206b1e8cf7c SHA-1: 2985099a67929ab5950d9db43e70dc595cac81c4 SHA-256: 8ad178efca809ae25b0e9554caa3fc0423341a67079e75c7a59121af242d587b
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or SEO poisoning campaign. The document body was unreadable, but the presence of numerous external links strongly supports the link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://aquamedicasatumare.ro/ckfinder/userfiles/files/53502438054.pdf In PDF document text
    • https://watertorens.nl/userfiles/file/73816849840.pdfIn PDF document text
    • http://e-hematologica.pl/users//file/valotepakiwisubo.pdfIn PDF document text
    • http://angerdress.store/ckfinder/userfiles/files/74597001223.pdfIn PDF document text
    • https://energooptima.hu/upload/File/zedosadebo.pdfIn PDF document text
    • https://horizontire.com/userfiles/file/96146461397.pdfIn PDF document text
    • http://graciaindoutama.com/kingkong/userfiles/files/barorolomaduki.pdfIn PDF document text
    • https://bykevin.com/wp-content/plugins/super-forms/uploads/php/files/ad481a11325e7566b12407a319e19250/kovezive.pdfIn PDF document text
    • http://www.asejnrtigers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1606f8472e6b68---8631013910.pdfIn PDF document text
    • http://dfh-consulting.com/userfiles/file/99251943956.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1609e6852c87ca---57435110128.pdfIn PDF document text
    • http://membranekeyboard.pl/_data/file/dubusamawivaridudar.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/jjbmas8vd8tm7aalt88uj2ag36/pijonufixubum.pdfIn PDF document text
    • http://cartonwrappingmachine.com/userfiles/file/bepamepalemetaxixizomabux.pdfIn PDF document text
    • http://worthingtonpark101.com/userimages/tipozudakisojadesud.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/1cf6d4d17d34dc2ab631e3661ca75500/79576112869.pdfIn PDF document text
    • http://zawayakw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607772ea0097c---zinidojodogixe.pdfIn PDF document text
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9e60a121c5---51945335869.pdfIn PDF document text
    • http://logo4you.dk/userfiles/file/90771936815.pdfIn PDF document text
    • http://countrysquirefoods.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608417bc64d24---38036081484.pdfIn PDF document text
    • https://arhometutor.com/userfiles/file/tejarabiwesufinijuwol.pdfIn PDF document text
    • http://smiletoursvietnam.com/ckfinder/userfiles/files/25473033760.pdfIn PDF document text
    • https://karapinarinsaat.net/userfiles/upload/file/xezovidibiboloranuxozudub.pdfIn PDF document text
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088f84e6486b---48816127664.pdfIn PDF document text
    • https://foxtailmag.net/wp-content/plugins/super-forms/uploads/php/files/6fee4987600f30a96742973c471c260b/tezetapoki.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=science+equations+and+formulas+pdfPDF link annotation
    • 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_off0000e5ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5ED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fdff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDFF 18280 bytes
SHA-256: 81d106a810a726d08941f71ff58cb47685444e7aec36b1e1f204d7dcf08ab9f6
font_02_sfnt_off00012d0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D0D 11100 bytes
SHA-256: 9b3b0e9a3192b4699bfe46e024c5f5398b951980603532ef68629649baf6932d