Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa6fa82dcabef396…

MALICIOUS

PDF

70.2 KB Created: 2021-09-29 13:04:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 27193cd7b3a5f9e6140214b0687c0269 SHA-1: 6c5f351497529b96ab45c9c5c305d068155750ad SHA-256: aa6fa82dcabef396931bf20217b605321a3e2c820b1866180a0e756c9cf1662b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a link farm with numerous URLs, many pointing to compromised or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' indicate a pattern of distributing links through potentially untrustworthy sources. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

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://efckrakow.pl/userfiles/file/pufimilabovejan.pdf
    • https://rajatotogroup3.com/contents/files/94102246216.pdf
    • http://mixline.ru/img/lib/file/guwumabovakujefuso.pdf
    • https://monyetmesum.com/contents/files/23140925216.pdf
    • http://schokozentrale.de/idata/kopowobop.pdf
    • http://buzmakov-ua.ru/admin/ckfinder/userfiles/files/vuziba.pdf
    • https://www.weboonline.com/ckfinder/userfiles/files/dunemumopudaf.pdf
    • http://ysenb.kr/board/file/editor/file/danewemepeweralelos.pdf
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16132c0215e4de---felatelixixed.pdf
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/1613598eb8c5df---fubowesetimezisezetima.pdf
    • http://residenceraffaellotorino.com/userfiles/files/76738847276.pdf
    • http://fzcce.com/aimgs/uload/files/64524112220.pdf
    • https://santevita-bg.com/ckfinder/userfiles/files/juxefesokabelatipu.pdf
    • https://bitree.com/ckfinder/userfiles/files/zowenoboraduvumuzujukemiw.pdf
    • https://stockbauer.hu/uploads/file/labejufa.pdf
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/161402c9b49929---79440803045.pdf
    • https://unique-u.biz/images/uploads/file/xezul.pdf
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/p44ukuk7u6anflrdel8rj7c4gc/62458493516.pdf
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614cf95c2bd39---98122454059.pdf
    • https://yesilkoyluleriz.biz/resimler/files/36589418858.pdf
    • http://newgrids.com/userfiles/file/11803788719.pdf
    • https://taiwancy.com/app/webroot/userfiles/files/59186295566.pdf
    • http://pscemetery.com/userfiles/file/8903164071.pdf
    • http://qhzs88.com/admin/fckeditor_upfiles/file/2021090217484480554.pdf
    • http://nhanvietgroup.com/demo/xay-dung-tnx/upload/files/vanolajipujukovupo.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=xos+launcher+pro+apk+download
    • https://tes-sys.com/uploads/ckfinder/files/20210923/16323794178093.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_off0000b1e0.bin
cdc1fb18042a1e61f1b564849ed424488d79f2b64bedc1a852b25c50ec8b7ec8
pdf-font-stream PDF embedded font (sfnt) at offset 0xB1E0 15912 bytes
font_01_sfnt_off0000da92.bin
4337b44986c2ea3991c21648c48c32b40922cad50de980297496209150f4c45b
pdf-font-stream PDF embedded font (sfnt) at offset 0xDA92 10704 bytes
font_02_sfnt_off0000f323.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF323 16792 bytes