Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa7900ae7c9b03de…

MALICIOUS

PDF

78.4 KB Created: 2021-09-18 06:50:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 14adb9d05c8c6840a9648e441d607967 SHA-1: 12688ae67cfc646d666914bc17edd8172413a9b1 SHA-256: aa7900ae7c9b03de5ae120fe7d172495e27828880d74e77e8e5a4173b0f036a7
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to external resources, many of which are hosted on compromised websites or disposable domains, indicating a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the PDF structure itself is used to host and link to potentially harmful files.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://dentish.ru/ckfinder/userfiles/files/zawaromijugulabazoxoweted.pdf
    • http://ambulatorioveterinarioscapindandrea.it/userfiles/files/bugajuwi.pdf
    • https://bwawarszawa.pl/upload/file/37621778860.pdf
    • https://ebus.myskoolapp.com/FCKeditor/FCKimgUpload/file/21285168743.pdf
    • http://iwayman.com/uploadfiles/file/2109091150106002861mvgpd.pdf
    • http://azizavacanze.com/userfiles/files/dedewuwad.pdf
    • http://chuanghuilaw.com/filespath/files/20210916115254.pdf
    • https://pierrelemagicien.com/userfiles/file/gulazure.pdf
    • http://onsijsselstein.nl/userfiles/files/1810203959.pdf
    • https://feriaesotericadeatocha.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135f85494115---xifarusetetubiw.pdf
    • https://radmangroup-ye.com/rgfiles/file/fejoxonadedul.pdf
    • https://epponline.com/mentorfinancial/page_images/file/tetivolemuj.pdf
    • http://ferrogep99.hu/static/media/file/81288058215.pdf
    • https://yuktiedu.com/wp-content/plugins/super-forms/uploads/php/files/92275a39b0bf8a0865c0b6405f9a8e78/72787480316.pdf
    • http://naitikfashions.com/ckfinder/userfiles/files/xijateletulu.pdf
    • https://oykufestivali.com/ckfinder/userfiles/files/bematakomuzatarodin.pdf
    • http://atsolution.org/userfiles/file/20210914142417715426636.pdf
    • http://jnnycc.org/userfiles/file/43671830113.pdf
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/4c08747870ac33313c5857c24ffba493/gadifinagezu.pdf
    • http://viettranslators.com/webroot/img/files/xugagi.pdf
    • http://sportingfoundation.com/uploads/file/90423763846.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=understanding+mathematics+class+8+book+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_off0000ca28.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCA28 16792 bytes
font_01_sfnt_off0000e23a.bin
eefc5831c4dab734cefe853ccd114d98b997bdda529776687b8268f7271a41b3
pdf-font-stream PDF embedded font (sfnt) at offset 0xE23A 18080 bytes
font_02_sfnt_off000111b2.bin
bbcb902c5d992a6252be2f249e0a909056e57cb6f1a054abb8665c8eb94fe122
pdf-font-stream PDF embedded font (sfnt) at offset 0x111B2 11516 bytes