Malicious PDF — malware analysis report

Static analysis result for SHA-256 73f9b646fb6917c8…

MALICIOUS

PDF

88.4 KB Created: 2021-06-29 03:26:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 77c330844fbedd2bcaa3f176a54317b2 SHA-1: 0e1e2b5fd3da78173de970f5664c8fd7cb6e2ed1 SHA-256: 73f9b646fb6917c890bdfddc417e4f63f64b7b2b4c3d848de0389d4ee9319005
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to compromised WordPress sites and other domains, suggesting it functions as a link farm to distribute malicious content or phish users. The presence of external URI heuristics and link farm indicators reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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
  • 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://huntic.ru/uplcv?utm_term=i+am+a+rider+audio+song+download+mp3+naa+songs
    • https://voicelux.ru/wp-content/plugins/super-forms/uploads/php/files/83cbd1fda1765ea6c10d691e1412751e/wosisogesesixofa.pdf
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/e88343740589f8ea39775dbea2bf5918/fafetazuv.pdf
    • https://sitebyside.ru/wp-content/plugins/super-forms/uploads/php/files/6eca351b12d15158fab9f85a61d5a52d/saloburiwobakilaboruvi.pdf
    • https://soudurelauziere.com/upload/editor/file/tejewif.pdf
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/ba03902bd28fceee433155265cbaa6bc/vobotobopebo.pdf
    • http://n2nlah.org/UserFiles/file/vedopojobuzudavefo.pdf
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b508bf3a32a---nawudenapedug.pdf
    • http://www.redactordecontenidos.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160801959afac3---tidowopodalolosiguwuw.pdf
    • https://accesoriosalmayor.com/images/userfiles/file/80255044681.pdf
    • https://wills.sg/wp-content/plugins/super-forms/uploads/php/files/af4caa2f7176c4a05e1e87ffd2d066ec/25799728701.pdf
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/e8b9ea11e6da98a3a034edd1942283ea/sejazajozomewuxitilapami.pdf
    • http://e-hematologica.com/users//file/zonewinanikepakizaketig.pdf
    • http://jhdjt.com/images/upload/File/vipokone.pdf
    • http://www.chatanakonci.cz/userfiles/file/vogelavojonixis.pdf
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/o5tejhfvi9k9i2em23thcqipv8/lurefadutatuf.pdf
    • http://dzbnf.com/upload/file///jukoruperogujovagijuzomi.pdf
    • http://njuhome.pl/ckfinder/userfiles/files/tajejoranitidaredonifu.pdf
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/f9b70eaa4e88b03ad9174b153e029403/xofonapawezame.pdf
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/16077e50b4d277---gopulo.pdf
    • http://creativetechno.in/userfiles/file/21670866405.pdf
    • https://argumentua.com/i/file/wikesisijegenewuxiselem.pdf
    • https://www.arphplumbing.co.uk/wp-content/plugins/super-forms/uploads/php/files/rfbituc3kgg3s93n05gf5jtosc/84854823401.pdf
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca57441ef4---80525642181.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f640.bin
f2fee3b0637fb9333983329d523798ac21d5b61e94b9e63093bd4be5b4330f18
pdf-font-stream PDF embedded font (sfnt) at offset 0xF640 16988 bytes
font_01_sfnt_off000122c0.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x122C0 16792 bytes
font_02_sfnt_off00013ad7.bin
f8e23f7e68001cb719a29730ab54297aea32b17aeeafd7a3223c9cb81ae0aad1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13AD7 10948 bytes