Malicious PDF — malware analysis report

Static analysis result for SHA-256 fa5a9931871437bc…

MALICIOUS

PDF

89.7 KB Created: 2021-08-18 22:23:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ef35ae76ccfe2aa383d61d8edc3b2648 SHA-1: afc60dc67200e854e77e17349314c26fcd0de037 SHA-256: fa5a9931871437bcc342f7f0864157f81763cc8f171cc8be6cc0316231985b7c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links pointing to compromised websites and disposable hosting, indicative of a link farm used for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent, specifically identified as a phishing trojan. The document body is heavily obfuscated and unreadable, providing no direct user-facing content but reinforcing the malicious nature through its structure and embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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 http://zhengfutz.com/v15/Upload/file/2021822354577680.pdf
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608439f06d081---44663876528.pdf
    • https://www.entornopublicitario.com/wp-content/plugins/super-forms/uploads/php/files/c0f7206222b6248d436a2d06dbaea2fa/kelagafawojanifukerugeped.pdf
    • http://austria-ex.com/images/blog//file/nidokidejik.pdf
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16081e9ac5ba60---61224391692.pdf
    • http://littlepearlbooks.in/data/eimages/file/95111197671.pdf
    • http://atomleasing.ru/media/File/melili.pdf
    • https://lawrenceyezersky.com/userfiles/file/pilagalulujabaj.pdf
    • https://aimara-bg.com/userfiles/file/sokunoluji.pdf
    • https://ce-mi.pl/uploads/userfiles/files/vimavupifijaz.pdf
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/1609548d9184bf---dilumobawod.pdf
    • http://kryotherapie.net/neu/userfiles/file/57166306233.pdf
    • https://www.stamfordtaxis.com/wp-content/plugins/super-forms/uploads/php/files/340bj2l1uk9ii746qgaivfl8q6/1278725324.pdf
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/nei4a4eqiuajunras9eod7u7gj/34604567769.pdf
    • http://hoteldarim.ir/basefile/hoteldarimir/files/kezemogun.pdf
    • https://hafa-verein.de/wp-content/plugins/super-forms/uploads/php/files/a07853fe11dafe2ed03c4dca263d6c22/8582359690.pdf
    • https://rumusjitu.com/contents//files/pozivo.pdf
    • http://easytravel63.ru/ckfinder/userfiles/files/dowepo.pdf
    • http://mopron.ru/upload/files/lilumak.pdf
    • http://xn--80age2amlc.xn--80adxhks/pics/images/file/biruzozitasajuke.pdf
    • http://modero.vn/upload/files/xesawafulapijuvut.pdf
    • https://best-label.com/upload/files/59022682873.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=teenage+mutant+ninja+turtles+season+3+episode+15
    • 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_off0000f905.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF905 16792 bytes
font_01_sfnt_off0001111c.bin
2a657e14f12a0d56e6d4782429aefc86113045d959f58f299b9ace3b1d60abf3
pdf-font-stream PDF embedded font (sfnt) at offset 0x1111C 11284 bytes
font_02_sfnt_off00012b66.bin
ca15972e04781c3841904cd086a4a257dd890e2d7607d7ff1de282db0c1791d9
pdf-font-stream PDF embedded font (sfnt) at offset 0x12B66 17192 bytes