Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c128724c9caab6b…

MALICIOUS

PDF

95.8 KB Created: 2021-06-25 12:09:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 36a9fe0d23854132d26aa86ad9e48e1c SHA-1: f3567cde4f7e47289dc87a10c505c05d7ebda8c6 SHA-256: 3c128724c9caab6b7c48d78cc1f459b6f0cc4e2d5c65ff55f80fd91018cfecfc
156 Risk Score

Malware Insights

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

The sample is identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Numerous embedded URLs, including those hosted on compromised WordPress sites and link farms, suggest a phishing or malware distribution campaign. The document body is heavily obfuscated, preventing analysis of its direct content, but the heuristics strongly point to a link-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • 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.
  • 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://krisoc.ru/uplcv?utm_term=foye%27s+principles+of+medicinal+chemistry+7th+edition+pdf
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/e5e2f815f50006dbea9f30e1ddac030d/4258757836.pdf
    • http://www.physedu.in/newsite/userfiles/files/35690954106.pdf
    • http://basaritarim.net/admin/editor_resim/file/zowufujumexigu.pdf
    • https://djhelaly.com/wp-content/plugins/super-forms/uploads/php/files/02a125c57d876ff35494d5530a8257c8/51544745679.pdf
    • http://www.mediacomriccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/160d1dc5fd13ff---vamuresexizevisi.pdf
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16096443938f1b---gebajezobupajer.pdf
    • http://ildungrice.com/fileupload/fckeditor/file/47027428741.pdf
    • http://dokumsuzgec.com/userfiles/files/xetomeludonepedefudeta.pdf
    • http://ergo-logo-bamberg.de/userfiles/file/sijizoweji.pdf
    • http://apelasyon.com/img/userfiles/files/nepimokinaxugepofo.pdf
    • http://www.danvillern.com/wp-content/plugins/super-forms/uploads/php/files/jovop6f1mudrjoqb74scrmscb4/3543154443.pdf
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc1ef59838e---pogeket.pdf
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c57ff3ad36e---rovegosu.pdf
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/ec4de31e12f1e0863285c27d86dcdd38/86378332069.pdf
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d1ff36e276---45249008141.pdf
    • https://www.webplease.it/wp-content/plugins/super-forms/uploads/php/files/fg1dud1lelog500006pf6pg4c5/28179839093.pdf
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/c7e19e8f99f4e8e0b2a9032e347c6556/19649616775.pdf
    • https://www.truegridpaver.com/wp-content/plugins/super-forms/uploads/php/files/c3d33064707434431a1ce1722cd4084a/kepaw.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_003_off000100a2.bin
225ee779afc066dc532a7fdca0ae70da86964f9b94a6057957dba611cc0cdf21
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x100A2 21544 bytes
font_00_sfnt_off0000e891.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE891 16792 bytes
font_02_sfnt_off00012634.bin
32d6c41a90458a7a55cdff0f5e1f610f07fa7d5f1a54cf1884dbe0cb4060a71e
pdf-font-stream PDF embedded font (sfnt) at offset 0x12634 11060 bytes
font_03_sfnt_off00013fe3.bin
24c015a9a011c925ee3ab5a5b9a11d71236b3fa0ea13a53c5eb2d3754c26ea4c
pdf-font-stream PDF embedded font (sfnt) at offset 0x13FE3 18000 bytes