Malicious PDF — malware analysis report

Static analysis result for SHA-256 2807b2845b787a24…

MALICIOUS

PDF

76.4 KB Created: 2021-09-05 12:35:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1d914d8f23c5a73c679b7ad0a846cc1b SHA-1: ec41f1b55da6a6bae97f89c42ddab6ab9385aec0 SHA-256: 2807b2845b787a24e14512ad2f0343652011ea316fa812538abc061ff526b913
156 Risk Score

Malware Insights

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

The sample is a PDF document flagged by ClamAV as a phishing trojan and by an ML classifier as malicious. It contains numerous links, many pointing to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users to malicious sites. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic confirms this behavior, suggesting the document's primary purpose is to act as a lure for further compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9967

Heuristics 6

  • 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 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://hopkinshigh1966.com/clients/1/10/1054c114374c88b4a165e91103565d41/File/23510792546.pdf
    • http://anhuicrew.com/upload_fck/file/2021-4-29/20210429120223553942.pdf
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/83c446e0433ec420f194f1091f3ddcb1/28025743179.pdf
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ce504bc4e2---10977233496.pdf
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b8ffe9c4d30---30019524144.pdf
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d3dd1d2d412---tajumiwirakanutarakogusaj.pdf
    • http://anaminfo.com/attachfile/file/kezoxagofegilu.pdf
    • http://fairmonteast1969.com/clients/876766/File/xefiketarizaxaxi.pdf
    • http://cka-shiba.com/ckfinder/userfiles/files/wewexelefikololubekox.pdf
    • http://hysansam.com/fckeditor/userfiles/image/32202424396.pdf
    • http://learningkey.org/userfiles/13901572305.pdf
    • http://schokobrunnen.com/idata/rulupelapufogisozotebetu.pdf
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/160b05478a1037---dimuviwudijokonas.pdf
    • http://bscsaoner.in/ckfinder/userfiles/files/73859493444.pdf
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/9efbc514e759fb25b463a79fda845305/rigeniz.pdf
    • http://infrabud.eu/fckpliki/file/83583685433.pdf
    • http://nanobubblevietnam.com/uploads/userfiles/file/kesije.pdf
    • https://taybaite.com/userfiles/file/sujakeposesi.pdf
    • http://stomerijindex.nl/images/uploads/dasaforikorekezizuzot.pdf
    • https://aspaeng.com/files/image/files/finalonuvenumiripu.pdf
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/a27fb86108d11beefc7678af6cc46bdb/69772322530.pdf
    • https://expresstestingatl.com/wp-content/plugins/super-forms/uploads/php/files/fbdc0ac919b4de7b4ee48db87fe1e3d2/93570085996.pdf
    • https://stakeoutllc.com/wp-content/plugins/super-forms/uploads/php/files/850c7e502539e75ee1647fd224d1ee71/33289427482.pdf
    • http://cheumst.com/upload/fckeditor/file/savunigaj.pdf
    • http://amuseonline.com/absite/userfiles/file/kibivovaximawosel.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=hydrocarbons+class+11+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_off0000c6ea.bin
df7d3ed7f1e91590be2d57831465169703c7eb6bf008f95760b2e3f31f4eb931
pdf-font-stream PDF embedded font (sfnt) at offset 0xC6EA 10588 bytes
font_01_sfnt_off0000defb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDEFB 16792 bytes
font_02_sfnt_off0000f70d.bin
f9e2a368e42d6b6232c1e3cfb446f23d914fa50919b07ea9af277a12fb683cb4
pdf-font-stream PDF embedded font (sfnt) at offset 0xF70D 17704 bytes