Malicious PDF — malware analysis report

Static analysis result for SHA-256 1027b4587c5fd15c…

MALICIOUS

PDF

80.7 KB Created: 2021-09-06 08:52:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b68c0f828cd37c154dae3e5147f6de07 SHA-1: 067c5b5e820ee40e552194571518624835af2c86 SHA-256: 1027b4587c5fd15caf0680f8f9248f95614a179f34dda3f7cb0d17c27e8b7385
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with many URLs pointing to compromised WordPress sites and disposable hosting. The document body is heavily obfuscated and unreadable, suggesting an attempt to hide its true purpose, which is likely to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://web-sila.ru/wp-content/plugins/super-forms/uploads/php/files/666e4fd043ed947c0e8bac2f098c5011/liler.pdf
    • http://citra.cl/userfiles/file/lijuwofujerituxuv.pdf
    • https://taevlingar.se/images/pages/file/26225413318.pdf
    • http://tvkinter.com/file_media/file_image/file/tuvirutafukuziwilerizo.pdf
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ccfdfd36fe8---33903807448.pdf
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c8c72abfbd0---bimojazoxevi.pdf
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b8430c57950---xamelujikotamepozufiso.pdf
    • http://xn----8sbnbd9chja.xn--p1ai/userfiles/file/96580316054.pdf
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/qiimr4cj3s05cp3u37h7od4lrh/96195358227.pdf
    • https://workinhotel.com/upload/fckfile/fibojubipoxedizevi.pdf
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610402fdabf2a---xogonipilobovub.pdf
    • https://fortworthdental.net/cmsCart/upload/file/35420136724.pdf
    • https://detectiveoffice.net/userfiles/file/sotuwade.pdf
    • http://hrt-foto.hu/_user/file/11586082588.pdf
    • http://qishuochem.com/siicea/userfiles/file/sutiwimidan.pdf
    • https://www.supremecaravans.com.au/application/third_party/ckfinder/userfiles/files/muled.pdf
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16116ce48cbcd0---midasolewadofuwib.pdf
    • http://happyland-nsk.net/ckfinder/userfiles/files/wokenikojatoguti.pdf
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/djmtmk2a747gr5ssqhlbbq44n6/6714110089.pdf
    • http://dalnoboy.net/data/filestorage/upload/files/ratidilamiwa.pdf
    • http://rauvuonsach.net/images/uploads/files/xajazoxir.pdf
    • https://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/310nakce1lu8vvibgk3e42avid/nufunerubaxezufaritip.pdf
    • https://lederstuehle-shop.de/ckfinder/userfiles/files/63506084597.pdf
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/lksevumckl9q42jvq4f8v5uu4b/lukivibofetixox.pdf
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1606e330205a4e---57673128121.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=lansinoh+double+breast+pump+manual
    • 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_off0000d930.bin
e668a1f31d330f3cd758083fa947026ba46328ad16044c455bd34d2fc5d0d620
pdf-font-stream PDF embedded font (sfnt) at offset 0xD930 17100 bytes
font_01_sfnt_off000104a9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x104A9 16792 bytes
font_02_sfnt_off00011cc0.bin
2b58ce12f10ac5f3694beb37955d159711e9fd58feec2137e95e17318eb7b837
pdf-font-stream PDF embedded font (sfnt) at offset 0x11CC0 10856 bytes