Malicious PDF — malware analysis report

Static analysis result for SHA-256 3127b7115c8c9cdd…

MALICIOUS

PDF

85.7 KB Created: 2021-07-07 13:11:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 851d9e1faae6bd6f2598341eb412c5fd SHA-1: 2a1223ead4ae69b90f238a45a9770f637e02533b SHA-256: 3127b7115c8c9cdddd2abc3cfd6fa832681001aa587c30f2e2139061a2710071
166 Risk Score

Malware Insights

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

The PDF contains multiple links to external resources, several of which point to compromised WordPress installations. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to deliver a secondary payload or phishing content. The presence of PDF_RANDOM_URL_LINK and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics suggests an attempt to disguise malicious links within seemingly legitimate but compromised web hosting. No scripts were extracted, but the overall structure points to a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9765

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 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.
  • 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://chcial.ru/uplcv?utm_term=college+writing+skills+with+readings+pdf
    • http://aimecostruzioni.it/userfiles/files/11813031954.pdf
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609059ae577c0---27203320865.pdf
    • http://www.megasaludips.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a27d8f3d84e---fegajafakixoturago.pdf
    • https://akproauto.com/nbloom/fckuploads/file/57406082133.pdf
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/160adc6eed6899---viwugemixovotokimofobejuf.pdf
    • http://hitechdentalhouston.com/uploads/files/lefixilufiselajowirusi.pdf
    • https://vvpta-irvine.org/userfiles/file/9869075262.pdf
    • https://broadstripe.com/wp-content/plugins/super-forms/uploads/php/files/970b1f3ce732027c178701f96ee89d84/25368829806.pdf
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c6a34de5f7---reredusopagado.pdf
    • http://alexlunacoach.com/img/editor/file/93805987976.pdf
    • http://liebherr-tr.com/userfiles/file/76649159359.pdf
    • http://www.verneteco.com/ckfinder/userfiles/files/86501586418.pdf
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075c233bae6e---38957025626.pdf
    • http://rorolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/29537901067.pdf
    • https://childrencareandliteracysociety.org/userfiles/files/48249661291.pdf
    • https://akita-inu.lv/www/files/files/bowowuzijegujewesap.pdf
    • http://zhengfutz.com/v15/Upload/file/202152222363237.pdf
    • http://fandimnarodaku.cz/upload/file/85052850436.pdf
    • http://svx.su/ffile/file/62152002285.pdf
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160d8cd3518bb9---89229158381.pdf
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4e8380025a---43222900781.pdf
    • https://deltagroup.bg/uploads/file/xedakaxori.pdf
    • http://automotiveenergy.cz/userfiles/file/59880557738.pdf
    • http://akgikorea.com/file_upload/fck_upfile/file/71685186612.pdf
    • http://ty6600.com/userfiles/file/18628407522.pdf
    • http://megalaserasia.com/upload///5942907479.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c516.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC516 16792 bytes
font_01_sfnt_off0000dd2d.bin
5df657a66d3106718d642bd5fbdc36a0e71a0560d94ac96badc03f80b2fc41d3
pdf-font-stream PDF embedded font (sfnt) at offset 0xDD2D 10984 bytes
font_02_sfnt_off0000f683.bin
6d7d9b83396c234064a2f15d36720f0bf08960947bdabe8a2639a4d4737c63e0
pdf-font-stream PDF embedded font (sfnt) at offset 0xF683 16360 bytes
font_03_sfnt_off000120ae.bin
39ceb515980a046204d0d7a904cef90a10430614cf86325080e5523745d7d2f6
pdf-font-stream PDF embedded font (sfnt) at offset 0x120AE 12832 bytes