Malicious PDF — malware analysis report

Static analysis result for SHA-256 bde53140c00523c9…

MALICIOUS

PDF

81.1 KB Created: 2021-09-04 16:46:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7270d0c38d735d9fd51e6354ff3f7a0d SHA-1: 07eca5d8a62d1328bd95433220700fc38570d536 SHA-256: bde53140c00523c9c7cb807cd20b43e5dcf8e59016016df41e97754d0912d93c
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 compromised WordPress sites, indicating an attempt to lure users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://kbchina.de/upload/99141692933.pdf
    • http://mirrorgallery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e7fdf3266ca---fidofumujufaduto.pdf
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a422a58e3bf---59390017516.pdf
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ed878092f6b---muzanepunesozofu.pdf
    • https://ahreco.com/uploads/news_file/bepadoweve.pdf
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609d4c4199839---zugesexewudujubijowemis.pdf
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/9ccaac98ce89fac28a86ce094447187a/82307790615.pdf
    • https://arerp.kr/data/file///36694670137.pdf
    • http://jeyadhurgatemple.com/userfiles/file/giwukovexewafi.pdf
    • http://acunambalaj.com/adenoto/upload/files/fuwasozasaxolukapekaweja.pdf
    • http://ngnjl.com/userfiles/files/vomuginupubenimiwotokosu.pdf
    • http://motorlustor.net/userfiles/file/2266432014.pdf
    • http://infunplastic.com/d/files/rewubovusoxut.pdf
    • http://akwarella.pl/user_uploads/file/xakobejufob.pdf
    • http://vector-luczak.pl/new/fck_user_files/file/tuxatiwataveginutew.pdf
    • https://www.emma-solutions.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608b48c950307---44742013304.pdf
    • http://coopmong.com/ckupload/files/jamujesivizoje.pdf
    • https://highrise.pl/file/kexamonojuxubewafoxodeve.pdf
    • https://www.sanier.pl/wp-content/plugins/super-forms/uploads/php/files/qk5t8a18gbetd2uutasjqd05ve/maxozidojav.pdf
    • http://cyklo-sport-servis.cz/UserFiles/File/bejegirudozagawijiteruso.pdf
    • https://invest.pl/userfiles/file/77087655418.pdf
    • http://bahattinburyan.com/userfiles/file/fanepewi.pdf
    • http://harryreichert.de/uploaded_pics/News/file/80539393618.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=transport+of+drugs+across+biological+membrane+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_off0000d5ed.bin
70a7a977bea321ea7ce6567483e0b8f878a378841c84b4334209fe073a76878a
pdf-font-stream PDF embedded font (sfnt) at offset 0xD5ED 17940 bytes
font_01_sfnt_off0001045b.bin
1ba335ed9fd4e5d149bdf7dfade489454f840a660c041d82ed55fda56ec7ce26
pdf-font-stream PDF embedded font (sfnt) at offset 0x1045B 11168 bytes
font_02_sfnt_off00011e06.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11E06 16792 bytes