Malicious PDF — malware analysis report

Static analysis result for SHA-256 16851f0b2ddff38f…

MALICIOUS

PDF

82.5 KB Created: 2021-07-21 13:16:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 05959ed84b967799e161a174100e92d1 SHA-1: ebd608ee79dcc6f4616fc403e5f263e3d71a6334 SHA-256: 16851f0b2ddff38f552145e4676c2c82d51b7f9561bfb3874c56d1f2dd9dfae3
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics, including a critical ClamAV detection for 'Pdf.Phishing.Trojan'. The presence of embedded JavaScript and a large number of links pointing to compromised CMS uploads strongly suggests a phishing or malicious content delivery attempt. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall pattern indicates a malicious intent to redirect the user.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://anhuifan.com/upload_fck/file/2021-5-7/20210507011224804064.pdf
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/160c97d280a683---93989544035.pdf
    • https://stakeoutllc.com/wp-content/plugins/super-forms/uploads/php/files/0ecaceb3d0e0e2b5cdbd00ffb0bc5f58/4102508013.pdf
    • http://arunimaflavours.com/userfiles/file/denadel.pdf
    • http://abwcoliseum.com/uploads/files/52241904530.pdf
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/77f00c9654ec196c6f3fde6dc129bf00/93675434282.pdf
    • https://www.alpha-dynamics.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1606f6570aa746---93502262575.pdf
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b1386a640ed---tukesiwigotakojix.pdf
    • https://gotoko.com/cmsv2/upload/files/94846790289.pdf
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098432c11def---47853284650.pdf
    • http://garderoba.sk/images/_file/basonufijopedosavani.pdf
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aed343c4f59---52518672483.pdf
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160874385ce838---rudujimulib.pdf
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/5ea88aad1dd64c533d37ebf2c85e9fe7/69815769940.pdf
    • http://technoauto.jp/js/upload/files/31430043752.pdf
    • http://eros-arena-reutlingen.de/eros/userfiles/file/xigimukukeli.pdf
    • https://okazdedziecko.pl/_files/Media/file/75676753996.pdf
    • https://maidintown.co.uk/wp-content/plugins/super-forms/uploads/php/files/605f6f46f8066cc5b56fe1377123e123/juritikewiboxonuxofuxunot.pdf
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5429878297---laxazuzemakawi.pdf
    • http://brandweeramsterdamamstellanden.nl/userfiles/file/57209273616.pdf
    • http://guitarenko.fr/img/files/legezadetifar.pdf
    • https://ivaco.it/file/1761630989.pdf
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/rh61mc46gj47in416bni49pgt0/daluvubupafogipupoxuz.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=how+to+make+a+ball+with+rubber+bands
    • 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_off0000df16.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF16 16792 bytes
font_01_sfnt_off0000f72d.bin
092c3d9bf25fe4094f44095188d83327f05c99432ef8118b8287ef0b3c03bb2e
pdf-font-stream PDF embedded font (sfnt) at offset 0xF72D 10920 bytes
font_02_sfnt_off0001103e.bin
45466e194e340bbbf79c7cff502013379daffd8dac17c8cfa044a31e581498e2
pdf-font-stream PDF embedded font (sfnt) at offset 0x1103E 17172 bytes