Malicious PDF — malware analysis report

Static analysis result for SHA-256 c72bc941b41b602d…

MALICIOUS

PDF

80.4 KB Created: 2021-09-08 10:03:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: b66f7b3f00a8a4fdb6053bc9a38f81c3 SHA-1: 6f06a52ca6d74a47e59f15171c1727705ecf1dbd SHA-256: c72bc941b41b602d9783bd96436e1a0cb7f66981631dc67a78d15d8ec80d6b02
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a malformed stream and numerous external URIs, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to distribute malicious content. The presence of embedded URLs and the nature of the heuristics indicate an attempt to trick users into downloading further malicious payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7217

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
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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
  • 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://garglob.ru/uplcv?utm_term=defining+and+formulating+the+research+problem+pdf PDF link annotation
    • http://rayanchem.com/d/files/rulisel.pdfIn PDF document text
    • https://lienlacanien.com/img_pages/file/8602600005.pdfIn PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/160fdb0612eac1---wutuvepuxupelutip.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e0fd49ec5c---33446468068.pdfIn PDF document text
    • http://www.grupohk.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ad3517ed257---peposilunorov.pdfIn PDF document text
    • https://alzubidi.com/userfiles/files/zujubefogugerefeki.pdfIn PDF document text
    • https://evg-prague.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1606c782e2bacd---5290439337.pdfIn PDF document text
    • https://enville.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a1a035032f---nerorapenasuw.pdfIn PDF document text
    • https://canevastoilestjean.com/upload/editor/file/51467398306.pdfIn PDF document text
    • http://firegallery.ru/img/upload/53238236179.pdfIn PDF document text
    • http://gewald.ru/content/Files/votigizadolikonupikokuxo.pdfIn PDF document text
    • https://hunglivet.com/uploads/files/202109010711208249.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/15445468974.pdfIn PDF document text
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f768cb2f1dc---77436056113.pdfIn PDF document text
    • http://lokalizacja-gps.pl/userfiles/file/wazelilova.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609312c6e7fd0.pdfIn PDF document text
    • http://bagiez.de/userfiles/file/divute.pdfIn PDF document text
    • http://lbs.ac.at/wp-content/plugins/super-forms/uploads/php/files/crkccnnpqamut45hi1rl5otshl/65421146561.pdfIn PDF document text
    • https://cradlegold.com/wp-content/plugins/super-forms/uploads/php/files/cr0oq4pqd1h8j1ii8rjojuge4q/13916560498.pdfIn PDF document text
    • https://thefertilizerequipment.com/d/files/25418958823.pdfIn PDF document text
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/160805958821bc---69089639446.pdfIn PDF document text
    • http://comp-art.ru/userfiles/file/2896987458.pdfIn PDF document text
    • http://morpheus-architects.com/file_media/file_image/file/76122423950.pdfIn PDF document text
    • http://podhoru.cz/userfiles/file/94111199897.pdfIn PDF document text
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160aa2c3f6f486---97516204526.pdfIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f274.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF274 17948 bytes
SHA-256: 47ff598518fc46e27e0520ab7acea96c16f612972c49972559252f1e12d3394d
font_01_sfnt_off00012102.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12102 11308 bytes
SHA-256: c4b769112b4ad303e7f9af7809f940068997e4f5014e1a6ebe24e4a290dbcb6b