Malicious PDF — malware analysis report

Static analysis result for SHA-256 852cd311bc8803bf…

MALICIOUS

PDF

74.0 KB Created: 2021-09-19 16:08:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: eb3c78dceefeb255dafd9e1a2f896835 SHA-1: de1201a5d2044d487ae431c884f935c37a29b902 SHA-256: 852cd311bc8803bfc89f3d00ed9a717ffcccb358f61eb8fe2f81e91532804fab
196 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many pointing to compromised WordPress upload directories and disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of embedded URLs and the nature of the links suggest an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

Heuristics 7

  • 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 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 https://smidgel.ru/uplcv?utm_term=best+free+movie+streaming+apk
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/161443aeb1a6ab---fomikinori.pdf
    • http://hiniceshine.com/upload/2016721817.pdf
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/ml47mc3shihletc82j6dparjo2/suporovesaxej.pdf
    • https://alakharia.com/public_html/userfiles/file/lesemod.pdf
    • https://belretail.by/ckfinder/userfiles/files/85760782520.pdf
    • http://drsrkbedcollege.com/ckeditor/ckfinder/userfiles/files/kixixizobolobapajujiteza.pdf
    • https://www.frontiermea.com/sites/all/libraries/ckfinder/userfiles/files/vekovafipepufoniniwu.pdf
    • http://study4student.com/cache/fck_files/file/21948603986.pdf
    • https://rakowka.pl/userfiles/file/lunakido.pdf
    • http://ngoinvest.com/uploads/ckfinder/files/30759451891.pdf
    • http://tupnate.com/ckfinder/userfiles/files/27428968528.pdf
    • https://bienenaktuell.com/sites/bienenaktuell.com/files/file/77873388776.pdf
    • http://thewesternmist.com/userfiles/file/24617671699.pdf
    • http://boldogelet.hu/media/10621889620.pdf
    • http://ghettaetamionarchitetti.it/userfiles/files/13412387821.pdf
    • http://tourhong.com/FileData/ckfinder/files/20210911_9792ACB3AAB78495.pdf
    • https://inlandautorepairmurrietaca.com/wp-content/plugins/super-forms/uploads/php/files/8232148b9b55450f8e2472c630dfacac/finekufodubuwifese.pdf
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ec7d62ae22---kagejovoge.pdf
    • http://smcertificationservices.com/userfiles/files/viluzudevibukixoduwim.pdf
    • http://pusheng168.com/uploadfiles/20210905183823.pdf
    • http://cathugo-catamarans.de/res/wysiwyg/file/wudavoxakogapa.pdf
    • http://tugrabilgisayar.net/resimler/files/95585980087.pdf
    • https://autopsrus.aerovents.com/ckfinder/userfiles/files/53570001942.pdf
    • http://merlegdoktor.hu/tmp/36726244906.pdf
    • http://lex.tj/img/file/74577818936.pdf
    • http://oodow.cn/upload/file/210912011810400715gg7pz0j6kdpr.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_off0000bc5e.bin
70e6ff5dcaf208b684bd906e32a07b5cab610d2e5404e854f97ceea399390254
pdf-font-stream PDF embedded font (sfnt) at offset 0xBC5E 17268 bytes
font_01_sfnt_off0000e936.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE936 16792 bytes
font_02_sfnt_off0001014d.bin
7d19f8daab20e23550041b2e32b66dcbc114437e64e772d40315cff7f0b31721
pdf-font-stream PDF embedded font (sfnt) at offset 0x1014D 10864 bytes