Malicious PDF — malware analysis report

Static analysis result for SHA-256 adfd88d0bc08eebc…

MALICIOUS

PDF

79.0 KB Created: 2021-09-23 13:46:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5a9546922cc68b5403e9c6c12db3efbf SHA-1: 413534eb9aa5bca197ec8b6ecde48b9c3a9ec723 SHA-256: adfd88d0bc08eebcf729521d7147efd823c62df9adac399a15b81e669a46a8cb
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this, indicating the PDF's primary function is to distribute links to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • 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.
  • 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://leanuslab.com/UserFiles/file/36183206040.pdf
    • http://gd-weimi.com/upfolder/e/files/20210911035953.pdf
    • https://mmeasar.com/mmeasarfiles/file/44196868480.pdf
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/1614748c0b0c15---sudukomotab.pdf
    • http://studiocariola.com/userfiles/files/11365086256.pdf
    • http://terralis.net/catalogue_dynamique/file/dakotanuturizules.pdf
    • http://sgo-bage.com/public/files/files/mezepif.pdf
    • http://cuanhuadanang.vn/uploads/image/files/10154547397.pdf
    • https://laps.pl/userfiles/file/womizumepimi.pdf
    • http://radio-salsa.fr/php/rs/filesupload/file/25901190282.pdf
    • https://avigailpekelman.com/sites/default/files/file/36796557941.pdf
    • https://minjar.mebel18.com/uploads/files/79134875161.pdf
    • https://www.lavishlook.se/wp-content/plugins/super-forms/uploads/php/files/514b6ca9dec0be659867a01bfc43122c/zosurin.pdf
    • http://musicandyouapp.com/webupload/editorimg/files/10520412438.pdf
    • http://floral-design-lindgens.de/userfiles/file/68247940032.pdf
    • http://bociany.sk/media/file/35596954033.pdf
    • http://menifee.hanasushichoice.com/uploads/files/tudikugijutirojufije.pdf
    • https://resulgame.com/calisma2/files/uploads/26891401617.pdf
    • http://ydtmuhendislik.com/ckfinder/userfiles/files/53084575179.pdf
    • http://energosol.pl/images_cms/file/73906325444.pdf
    • https://bf-pomosch.ru/wp-content/plugins/super-forms/uploads/php/files/2t23f87vlth9i7fmp8lk5ba825/wagetaj.pdf
    • https://certifiedcollisionrepair.com/home/cert/public_html/ckfinder/userfiles/files/44611268583.pdf
    • http://schoonhovensvrouwenkoor.nl/ckfinder/userfiles/files/61386156837.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=rate+of+change+of+y+with+respect+to+x+calculator
    • 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_off0000cddb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCDDB 16792 bytes
font_01_sfnt_off0000e5ed.bin
37cd58f659e3925209f22ece18b9d4b7a71f4109af28c2869eee4d3578f95885
pdf-font-stream PDF embedded font (sfnt) at offset 0xE5ED 17548 bytes
font_02_sfnt_off000113be.bin
212c8121b3782e17abe48d6698e5b121062051f9b94cd18f07a94baed0917c75
pdf-font-stream PDF embedded font (sfnt) at offset 0x113BE 11204 bytes