Malicious PDF — malware analysis report

Static analysis result for SHA-256 266aa693fccd76a4…

MALICIOUS

PDF

73.8 KB Created: 2021-09-24 15:46:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 78070ea0d65cdce5bee93c11828b7930 SHA-1: 3b658be6379d682512d1116c3dbce4806b3527d9 SHA-256: 266aa693fccd76a4384135f3ef2f8ab67bde9dc1ff05225a526f5141e14c88be
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm with numerous URLs pointing to various websites, many of which appear to be compromised or use disposable hosting. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. The presence of multiple PDF link farm heuristics reinforces the conclusion that this document's primary purpose is to redirect users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9914

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://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/1612edc5fa03b2---ritesurusexabu.pdf
    • http://gpmpoolandspa.com/ckfinder/userfiles/files/tifoja.pdf
    • http://chipublichouse.com/ckfinder/userfiles/files/ruvurub.pdf
    • https://agriplan-rs.com/dados/ckfinder/files/vudituwosomuxupelafajotub.pdf
    • http://faw-asia.com/image/upload/files/zejexenifagiwejakojolev.pdf
    • http://61kidsclub.com/userfiles/file/vabotuwiku.pdf
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/7820l9aef33gf02i913codn7dq/19633389532.pdf
    • http://toeicspeaking.net/_UploadFile/Images/file/dasis.pdf
    • http://hzdsbg.cn/uploadfile/1631041455.pdf
    • http://antitumor.org/filespath/files/20210924150308.pdf
    • http://texmet.pl/userimages/file/22059512035.pdf
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613649ec3df42---muvege.pdf
    • https://www.blondel-bois.fr/ckfinder/userfiles/files/87100547547.pdf
    • http://uhy-th.com/image/upload/files/kewamufegufu.pdf
    • https://ruxthai-guesthouse-chiangmai.com/ckfinder/userfiles/files/vagufovidabu.pdf
    • https://arbormaster.us/uploads/files/bewifuguxa.pdf
    • http://alde-pace.org/ckfinder/userfiles/files/75565997274.pdf
    • http://nhakhoanhantin.com/media/ftp/file/xalawetototaruxapu.pdf
    • https://samsungklimalar.com/upload/ckfinder/files/72893949966.pdf
    • https://gregoryshow.ru/files/file/palas.pdf
    • http://ms-beauty.com/ckfinder/userfiles/files/58192849971.pdf
    • http://imbirimbir.ru/files/dujusepisedemukujizugag.pdf
    • https://www.prshots.com/ckfinder/userfiles/files/jatax.pdf
    • https://www.natursany.com/ckfinder/userfiles/files/getaxoverufor.pdf
    • http://connect-event.fr/ckfinder/userfiles/files/nekivek.pdf
    • http://dailymaytrogiang.com/userfiles/files/14931436969.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=bt+notifier+online
    • 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_off0000bbdf.bin
2703237f59d668e34169e87212990183b5fea14b5669d52b3942599acf5fcc8d
pdf-font-stream PDF embedded font (sfnt) at offset 0xBBDF 17884 bytes
font_01_sfnt_off0000e9bb.bin
97b2b93e7c7796f6a08f71ab285e88a771be23729518c2f65f238af8c57121c5
pdf-font-stream PDF embedded font (sfnt) at offset 0xE9BB 9928 bytes
font_02_sfnt_off0000ffc7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFFC7 16792 bytes