Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3a67539bca655b9…

MALICIOUS

PDF

116.0 KB Created: 2021-06-01 09:46:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ba71d82bc1e014a7c8255838634da780 SHA-1: 579f0dc11c31aacc32d144ef79d4ac6504d6904b SHA-256: a3a67539bca655b9897ad934be668fd11d1fd8f5a27b86367353173caf83a32d
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to compromised WordPress upload storage and disposable hosting sites. These links likely lead to further malicious content or phishing attempts, aligning with a spearphishing attachment attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://www.goldenlantern.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607415f6cafde---67276083309.pdf
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/vrkmdjuhp6e61qoqjjgkapvha2/ponuruzujurozowidejo.pdf
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/cafd023b07145f4328c3520020c48323/lufaligozerinizodafej.pdf
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/50bcbd6fe100f59dbae85403f3a8bcb0/47522036420.pdf
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/160a631a7ec083---bekamogozikugopetiw.pdf
    • https://teenvolunteer.org/wp-content/plugins/super-forms/uploads/php/files/eacc3e3ea33ec4b354c033b9d1c89630/natekegupojolu.pdf
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7fee011c03---natetepuju.pdf
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/bcf5e687fe269f0fc10b5a47b98b3838/3885137519.pdf
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096dca76cabe---madeponuseburob.pdf
    • http://elmiraclassiccountry.com/wp-content/plugins/super-forms/uploads/php/files/vgg5k15nadhgb3dgv9a4o0j3h0/modemidama.pdf
    • http://jtour.vn/userfiles/file/39954147077.pdf
    • http://sarljarry.fr/userfiles/file/xomepeduton.pdf
    • http://aihyang.com/userfiles/file/nowotajajasonemojikivezim.pdf
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f1866e28b8---vafux.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=the+seagull+chekhov+symbolism
    • 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
    • http://scripts.sil.org/OFL

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_006_off0001a35d.bin
2b4bcee5298caa2d1c9533e6a141e8846f077cf5e6b50f851635f39e8de47f73
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x1A35D 18436 bytes
font_00_sfnt_off0001669f.bin
ac59d59b0c6e1e6ddf16f0f69e826fc73890fed5c2af3e7cbfdf8f1fef8e39ab
pdf-font-stream PDF embedded font (sfnt) at offset 0x1669F 5432 bytes
font_01_sfnt_off00017909.bin
6cae2dd1f0743053640de2d997fd91d7b51645d4720f9fcc1a5b045636dd31ac
pdf-font-stream PDF embedded font (sfnt) at offset 0x17909 13244 bytes